Payment allocation

I took a loan at fasta my first payment was due on the 15th of January. They couldn't deduct from my account because I changed bank. But I paid Vai FET with the bank that I am currently using the mistake I made was to write their account number instead of reference so they couldn't locate the payment, so they started calling sending emails and sms claiming the payment, I explained to the consultants that called me I sent numerous emails with proof of payment but till to date they never allocate the payment. They even put my account on arrears which causes red flag on credit bureau. 15tth February i paid 2 installments , that made m not owing Fasta but still the 1st payment is not allocated. The last call I received was on the 19 March. 2025. I explained to the consultant she. Checked for the emails I sent and she saw the payment and she promised to resolve the issue by sending it to manager but to my surprise I just received an sms claiming the R369.16 that I paid. It looks like they want me to pay more as they don't want to allocate my payment to my account