sttom

I don't think you will be outright denied, as long as you have the supporting documents and (more than) enough evidence to support a bonafide marriage. You might have to jump through some hoops to rectify an honest mistake on your part. Or you might be lucky in "sneaking in" the date into the form DS-230 as mentioned in the "certificate of marriage".
One thing to note moving forward from here is: Although honesty is an absolute when it comes to immigration department, it doesn't really matter how it appears what happened, it matters what you can or cannot prove about the event, and with the level of ease. Things are much more straightforward here in the US when compared to other countries.
A marriage certificate means what it says it is: a certificate of marriage. If it were an engagement you would get a "certificate of engagement" (if there is anything like that in the country) .

I would believe that even in your country there is one and only one official govt body issued marriage certificate?
The reason i am asking this is: Is it possible, in your country, for one to say that "i am part-married"?
If there's only one "govt body issued marriage certificate" (no matter the first engagement followed by the marriage ceremony), when you submit the marriage certificate as the supporting document and they look at it as the primary evidence of your marital relationship and the date that the certificate says is when you were married in the eyes of USCIS. (For USCIS/NVC, a certificate issued by any other body/organization is just secondary supporting document).
Another way of looking at it would be, do you get another official document named "marriage certificate" with a different date after the ceremony/reception?
Keeping it simple: you said they rejected your I-129F petition in 2009 because of the "marriage certificate". In which case, they recognize your marriage and feel that you weren't eligible for a fiance visa in 2009. If the marriage was valid (to the USCIS) back then, its valid today too.

Depending on who actually pays attention, this may be caught by the USCIS during I-130 processing and issue an RFE. If not by the USCIS, you may be able to put the right date on form DS-230. Are there any consequences of having a date in DS-230 different from the form I-130? That would again depend on if they pay attention.
Either way, I would advice you to get things corrected before the visa is issued. Once its in the system, and the visa issued, you might have a tough time correcting it since it wasn't an administrative error on their part. (You will end up with June 2012 as the date in the immigration system while a certificate that shows July 2009)
And also,if not corrected earlier, a not-so-easy time during the interview since one of the questions that is most likely to be asked is "When did you get married?"
These are just my thoughts on the situations that could possibly arise.

Depending on who actually pays attention, this may be caught by the USCIS during I-130 processing and issue an RFE. If not by the USCIS, you may be able to put the right date on form DS-230. Are there any consequences of having a date in DS-230 different from the form I-130? That would again depend on if they pay attention.
Either way, I would advice you to get things corrected before the visa is issued. Once its in the system, and the visa issued, you might have a tough time correcting it since it wasn't an administrative error on their part. (You will end up with June 2012 as the date in the immigration system while a certificate that shows July 2009)
And also,if not corrected earlier, a not-so-easy time during the interview since one of the questions that is most likely to be asked is "When did you get married?"
These are just my thoughts on the situations that could possibly arise.

I would believe that even in your country there is one and only one official govt body issued marriage certificate?
The reason i am asking this is: Is it possible, in your country, for one to say that "i am part-married"?
If there's only one "govt body issued marriage certificate" (no matter the first engagement followed by the marriage ceremony), when you submit the marriage certificate as the supporting document and they look at it as the primary evidence of your marital relationship and the date that the certificate says is when you were married in the eyes of USCIS. (For USCIS/NVC, a certificate issued by any other body/organization is just secondary supporting document).
Another way of looking at it would be, do you get another official document named "marriage certificate" with a different date after the ceremony/reception?
Keeping it simple: you said they rejected your I-129F petition in 2009 because of the "marriage certificate". In which case, they recognize your marriage and feel that you weren't eligible for a fiance visa in 2009. If the marriage was valid (to the USCIS) back then, its valid today too.

A UK Consulate / British HC in Australia would be the 1st place I would look at.
Also, check if this helps. UK ACRO
I know for sure that this is for people residing in the UK, but you can email them your situation and they are pretty responsive to emails.
Email to ACRO