MTN SERVICE SUCKS

I called the call centre in regard to a problem. I am only able to phone some and line and the person helping me refused to give the phone to a higher authority and says he does not know why this is happening and his manager wont know either??? Pathetic service from mtn!! I was in store last week wanting to add a date bundle on my contract and was also told that cannot be done so I am using my limit to buy data and now i need to buy airtime all of a sudden to be able to phone landline number?? Since when mtn?? Seem like some numbers word and some not. I am highly dissapointed.