Problems with contract bundle

I don't know where to get help regarding my contract. I upgraded in January and I have taken a Made For Business M contract. As per the advert it was supposed to be for 400min and 6.5G of data. MTN is only giving me 200 min and 5.5G data. I have been to the store and I have made the staff aware of my problem. They acknowledged that there is a problem regarding my bundle and both the consultants that I spoke with promised to sort it out. It's been going on for weeks and nothing has been done. Now they don't take my calls or respond to my messages. I have 5 contracts with MTN and it's so frustrating that I'm being **********