Your story with the CBP had holes
U claim to have borrowed money for tuition and rent
BUT grandfather was going to pay
and was to rent from someone u had never met, instead of living on campus
BTW 40% of the tuition was due September 1st unless u do the MAV payment plan to pay in installments but that requires $1000 paid August 1st
and in this plan , tuition and room and board are covered so if u were paying on MAV plan, no need to rent from a stranger
Receipts were needed for holding your place at the university
copy of I 20 with valid travel signature
SEVIS fee receipt (I-901):
and since u already had and used F1 visa , u needed to show passport had multiple entry stamp
and u should have had copy of Financial Responsibility Statement
University of Texas (all locations) make it easy to pay online
Once you have signed your Financial Responsibility Statement, and your registration is complete, you will see a sentence on My Tuition Bill in green which states “Attendance Confirmed”. If you do not see this, you still have action to take.
CBP had all the information about the university as its all online and one of the officers would have checked it all out
And they would have checked with the university to see if u were enrolled