MTN FAILED TO CANCEL BIS SERVICES FOR OVER 5 YEARS!

My wife moved over from a blackerry contract to iPhone contracts over 5 years ago, but the stores failed to cancel BIS, and neglected to make us aware of this even though the contracts already came with data bundles. MTN continued charging her almost R200 per month extra for the BIS and data bundle that replaced it which I only became aware of when yet again recently upgrading again to ANOTHER iPHONE contract for which it once again remained unnoticed by upgrade consultants. We did notice the discrepancy between her contract costs and what they actually charged on her debit order and contacted them for which they notified us of this discrepancy and "resolved the escalated query" and said that they would reimburse her. Yet again this month they charged her the incorrect amount even though this was said to be resolved, and also NO credit or refund was received. Having her pay for a service that was never used or needed for iPHONE contract, and a service that was charged for every month as it does not even work on Apple devices.