Cellphone Contract Deactivated Accidentally

On 4 Aug I sent documentation to MTN to deactivate my mother's contract as she had passed away. Even though all the documentation was self explanatory, I also attached a letter and copy of my ID as I was requesting the cancellation. They responded asking for the handset or payment of R995, I returned the handset the next day. On 14 Aug at 09h00, I couldn't use my phone and received a \SIM not provisioned MM#2"error. I couldn't figure this out and by 14h00 I decided to call MTN. I was told that only MTN Legal could assist me because my account was in arrears"