CELL C REFUSING TO REFUND CREDIT ON MY ACCOUNT

Cell C has owed me more than R 15,000.00 since last year, which they acknowledge is due to me, but have still not paid back to me. I have emails from their credit department confirming it would be paid back to me, but every time I ask why it has not been paid, I am told to send them my bank statements to prove it has not been paid back to me. I send the statements each time, but they have still not paid it to me. I am absolutely disgusted with their service and have ported my number over to Vodacom. On my last call to them, I was told they can no longer access my account, as it is no longer active with them. I wonder how many other people's money is accumulating with them and no refunds are being made. I WOULD HIGHLY RECCOMMEND NOT USING THEM AS YOUR SERVICE PROVIDER.