MTN Contract Issues

I am once again posting about this still unresolved issue with this excuse of a company. I have now gone since March without a phone that i am paying for every month. I started this contract with Nonhlanhla from MTN Direct JHB office and received the wrong phone. I uave returned the phone in April and still no response despite me trying to contact this woman and her supervisor well over 30 times. Logged complaints and cancellation requests that have been noted and received reference numbers for. I then get a response via my previous complaint from Ishie of the complaints management department saying i will receive a phone call. No phone call and it's been 2 weeks now. This company needs to hire someone to give customer service lessons asap