Billing disputes

I took a loan of R8000 with Mfin in March 2017,my first billing of R1388,44 was taken off my account on the 20th of April, the loan was supposed to be 6 months with the last Debit going off on the 20th of September the amount was supposed to be R1100. I received a statement via SMS confirming that. To my surprise I was billed the R1388,44 I then called rainbow finance which transferred me from pillar to post until I spoke to a lady by the name Robyn who to my surprise Again said I'm in Arrears and she is not even able to read my statement. She requested I email her my bank statement with all the payments I made thus far. I did and she still has not gotten back to me. I am getting really annoyed and frustrated. As I feel no one knows what they doing. I need clarity in what's happening and a confirmation emailing a statement and that I am done with this loan.