Double debit order

My husband went to MNT to find out when he can upgrade and so he went for his upgrade on the date they have given him, but now the Debit order that went off this month is a double payment, when we request answers we were told that it's to early for a upgrade, so WHY did you do the upgrade, WHY did no one say anything how about we are going to double your debit order but NO NO one said nothing we must just sit back and oh okay just a R1700 off my back account...NO NO NO I want answers!! the after service is so bad really.. no one else pay a double payment when they upgrade why do we have to ??? MTN really we want answers and who gave you the authority to double the debit order from my account??