HELP-- Student Loan

I made a settlement agrremet with FAS Financial Asset management on which $1040.00 was to be paid on March 22,2007. The agent Mr. Brown and His supervisior Paul said I had to use a credit card. I did not have one so my brother used his. I havea fax that says a check must be sent it say this notice is to confirm the settlement agrrement of $2080.00 but does not mention the credit card payment which they charged. again it says what the fax saif (payment in the form of certified funds, cashier's check or money order.) They insisted on a credit card that day. Should I said a copy of the credit card bill?
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