It has been TWO months!!

On the 19th of January I took my phone to MTN so that it can get fixed. They said I will hear from them in a week's time. I only heard from them a month later. Today, almost two months later, after I accepted the quotation to fix the phone, I still haven't heard anything from them. I sent an e-mail to them, and they said they will reply to me within 1 business day, it has been 4 days. I am really disappointed with MTN's customer service. I am paying almost R500 a month, and this is the service delivery that I get??