Incorrect debit order

Good morning,

I am really frustrated with Netstar. I have been debited incorrect amount for 2 months. I upgraded my tracking device and they are debiting me on the old and the new contract. I did call last month and they said they will escalate the matter to finance. But nothing has been fixed on my account.

I feel like terminating my contract with them, because clearly someone is not doing what they are supposed to do.