Pathetic service from MTN Woodmead

I have requested for a limit increase and was advised by Lucas that he will contact me in three days time. This was three weeks ago. I have called several times and left messages for him which were not returned. I have called again and requested to speak to him immediately. The rude person who answered left the phone down and walked away. While holding on I could hear them talking about me and laughing. The call was eventually cut off. I have been with MTN for over 10 years and have never had to go through this issue with my contract. All I want is for my contract to go back to what it was - a limit of R150.00 is ridiculous for a client who has always paid on time and have never complained about the charges. Is MTN going to reimburse me for the call that I made and was put on hold without my permission???? I want a senior manager to contact me regarding this.