MTN Horrible Service

I've been a MTN client for over 20 years. Have spend hundreds of thousands with them. I recently upgraded my contract and gave the sales agent specific instructions. She acknowledged my instructions but chose not to capture it. I have since phoned client services and tried over 10 times to get through their call center. When I get through they cut the call or they just keep me on the line not saying a word, until I get irritated and hang up. MTN's service is going from bad to worse. I will phone today ro cancel my contract. This type os service is not acceptable.