MTN Legal administration does NOT EVER respond to ANY queries

I ported my contract to Cell C 6 months before renewal. I fell behind on the settlement of the ported contract from MTN on account number A ********** and was handed over for debt collection. I settled this account and is now in credit for the original R8122.09 I was handed over for. MTN has since then: 1. Billed me in full for a new contract for two years with the full outstanding balance in ERROR. 2. NOT answered any calls from MTN stores I have visited for help to return the credit amount due to me, or to remove the hold on my account. 3. NOT cleared the hold on my contract to even possibly stay with them and reneew a contract, since CELL C IS THE WORST!!!!!!!!! Even WORSE THAN MTN 4. NOT provided ANY WAY TO CONTACT THEM, since i HAVE NO VALID PHONE NUMBER on their automated system to get me to speak to a customer service consultant. 4. NOT responded to any e-mails from Hammond Pole Attorneys stating that the debt has been collected.