POOR service from MTN

I have been charged an excessive amount for data usage for 3 transactions whilst roaming. i am querying this amount with MTN via their business call centre and to date this matter has not been resolved. I first queried these amounts on 20 July and was promised that the URL would be sent to check what websites i supposedly accessed. URL was sent but those roamind dates were missing. i have subsequently phoned and emailed numerous times since them and all i have has are empty promises, suffice to say i am still waiting for the URL i received Aug month but i'm still waiting for July. this huge amount will be debited off my account tonight and then i know i will battle even more to reover my money. every call to the help desk has been closed without the issue being resolved. SO FRUSTRATED.....