Black Friday Special - False Advertising

We have been struggling with MTN to load the black friday special as advertised. Only getting 20gb data per month and not 100gb as advertised.

We have logged this call, and no feedback is given. we pay every month the amount due but we do not get the data as per the contract signed.

We are there every week and they cant give us any answers. so must we continue paying for a service that we are not getting?