Do not do any contracts via MTN 135 they do not keep to the promise

I planned to cancel a MTN contract via the 135 calls in line for a prepaid plan. The MTN consultant offer me a plan with 100 promotional minutes. I accept the offer because its wat what I was looking for, afterwords there was only 25 minutes on the plan. Although the call was recorded MTN did not keep to what they offer. Please do not do any contracts via MTN 135 they do not keep to the promise.