MTN misselling contact package (********* behavior)

I have a problem of MTN misselling a contract package to me. I called the retention department to cancel my contract and spoke to Kgosego from Retentions department. who advised that rather than canceling i can upgrade to a package that will include 500mb data and R55 airtime for as little as R39 monthly, and its been two months and and i only receive airtime and not data. I have numerously called the call center and never assisted. MTN has ********* tendencies.