Voicemail problems

I have suddenly had a problem that my phone does not go to voicemail. I have been an mtn client since 1996 and never has my voicemail not worked. //i have phoned the call centre 5 times and even went into MTN store twice.<br> Every time they say they are resetting it, that i should take my sim out and keep off for 15 minutes and then it will work.<br> I have done this every time and still the problem has not been resolved.<br> I am a small business owner and need my voicemail for clients to leave messages when i am busy<br> This has now been going on for 4 weeks and no progress.<br> <br> I get the same story every time that it is fixed but clearly it is not.<br> <br> What more can a client do - if i dont pay my bill I get cut off but when i dont have a service i pay for i get the run around.<br> <br>