GM Financial Consumer Loan Complaint

GM Financial Consumer loan department,

Installment loan Managing the loan or lease Texas

I was involved in a car accident on - - 2015 and I contacted GM Finical a few day after that and spoke to the total loss department and advised them of what had happened. I recived a letter stating that they are aware of the total loss. - - paid GM Finical the full amount owed on the loan on - - 2015 and they did not process it until the - - 2015 and than reported to the all - credit bureau that I was 30 days late and now has decreased my credit score - points and I can not purchase another car until they correct it. I contacted customer service and I was told that - would have to write a letter why it was late and I had - fax it to them and verified that it was received and it was over two weeks ago and was told it would take up to - hours to process and I contacted them today an nothing has been done.