Pathetic Service

I had a contract with Autopage for my cell phone. This was migrated to Vodacom in 2014 and my contract with them ended about 2 years ago. I was never in arrears and now two weeks ago i received a call from Nimle saying my account was handed over for R100. i asked for what and the lady said it was for the equipment that i had with Autopage. She couldnt answer my questions then i asked for a statement which she has to date still not sent. This is crazy. I was never in arrears and even if i was why was i not informed because i never missed a single debit order. They are not following procedure anyway. Why would you hand over an account without contacting the customer first informing them of the said arrears. I need this resolved as i am already under debt review so i dont need this ruining my credit record even further