Bad service & not helpful

I upgraded my contract about a month ago, the phone was freezing & the BIS didn't work, I went back to the store & they said it would start working. After 3 days I went back to the store and cancelled the upgrade. The consultant at the store said my contract will revert to my Top Up contract, she said she logged a request for Migration 7 it would take 7 working days. After 7 days it hadnt reverted so i called the call centre who told me NO request had been made & I'd have to put another request which would take another 7 days. On the 15th March I asked them to tdo a request, Its now the 26th March & it hasnt been sorted out. I've called the call centre numerous times & been to many different stores & all they say is it should happen but it hasn't, Today I get told by the consultant at the store that they cant do anything & have to wait & it might take 21 days. I've been an MTN customer for 15 years & never have I experienced such bad service, I'm actually considering cancelling this contract on a whole & going to one of the other networks.