Buymondo MTN

A Buymondo consultant sold me a data sim which was said I can use with my MTN contract in a dual sim phone. Mtn does not allow dual sims to be used on their network. Mtn refer me to Buymondo who sold the contract, and Buymondo refer me to Mtn. Unable to stop the sim I have not used and was sold with wrong information. Buymondo market as if they are direct Mtn, but then Mtn can’t help you with the issue. Have called and email multiple times with no success.