MTN's 808 Non existent or is it just me?

Is it just me or does MTN's 808 not work? My account was given to MTN when Nashua Mobile closed down in Dec 2014 as they are the service provider I had been using when I was with Nashua Mobile. I pay my account in cash every month, but my phone has been locked, I can no longer make or receive calls or sms's or use my data, this is very upsetting as I am paying my account every month and my account is not in arrears, I have been to 2 different MTN stores and at both stores I have been told that only someone at the number 808 can assist as they cannot unlock my phone from the stores. I have tried in vain for 3 months to get through to 808 but every time I call the phone rings and the call is dropped by MTN, not answered, just dropped. I need answers I am paying every month but I can't use what I pay for. Someone needs to get back to me please. REF No: ***, if I don't pay then they want to send threatening letters and list a person at the ITC, customers have no way of protecting themselves from MTN!