Being billed for moneys already paid

I have moved my contracts due to poor service. I am now being getting bills for R1.47 (desperation) of which I have already paid. After following up with the store I found that I am actually in credit of R453 but CEll C never called me to ask how they must pay this back to me - Account number ***. I am now being transferred from pillar to post and all departments are saying it's another department. I wish I had the bucks to put up another billboard display about this wonderful experience I am having with this company. Can someone please help me as I am deperatle seeking assistance in getting this sorted. I simply want to stop getting sms about a R1.47 I owe cell C and I just want what is due to me. my own money that is in credit. I understand that Cell C must make money - but does it have to be at the expense of their EX-Client's ???? Or If you really need to keep it and your company is that deperate - WHY NOT ADMIT IT TO ME AND JUST SAY SO???