MTN South Africa

I have given MTN 30 days' notice to cancel my contract and paid an agreed cancellation fee for early cancellation. Notwithstanding they refuse to release my number so I can move to another service provider. MTN has the worst call centre I have ever tried to deal with. The outlets are prevented from dealing with matters such as porting a number, so you are compelled to deal with the call centre.I have now been trying unsuccessfully for more than 3 months to transfer from MTN to another service provider. Avoid MTN and do not deal with them