Breech of contract

2015 Octber I was phoned by RCS to tell me that they have not received my payments on my account for July, Agust and Spetember 2015 and I must fax my bank statements as proof which I did. I have phoned umpteenth times and my account has not been rectified. Now they tell after 5 months that they want my target sheets so I fax and e-mail that and still my account has not been rectified. I can't use my card and I have been given up at the credit buro. RCS says I am in breech of contract after I have now proofed how many times that I did pay and never skipped a payment. Are they not in breech of contract now? I really do not know what to do anymore. I phone weekly and every other week I either fax of e-mail my proof of payments again and again. Someone please help!