NEVER UPGRADE ON THEIR REQUEST

I received a call from Telematics stating I can upgrade my x2 units even though the current contract is not done. I agreed and added a Beame on another vehicle. I have done the same upgrade before without sending a cancelation email and everything was fine. To my surprise this time round, I need to run after them to credit my account and to stop double billing 2 units that were "upgraded". I sent emails and to date I await a response. I reversed the last month's installment as I was not receiving communication and only then did I receive collection sms and 1 call from a collections agent who clearly needs training as she seemed to think I owe her an explanation after such incompetence. I let it slide as I had already called prior and spoke to accounts where they acknowledged the error (I recorded this). I was transferred to another department where they had to do whatever to ensure the account is credited, arrears removed and duplicates canceled by both accounts and this department. I received a cancelation email and thought all is in order though an sms of a unit installation was also sent??? To my surprise, a debit for the same amount as last month is yet again debited after all of that, seriously? It has been 4 months of this mediocre service though the 1st month I figured there might be a pro-rata rate, to which I was told there was none. I am not sure where my confidence is in your company if correcting a measly account can be such a challenge. If this cannot be resolved, help me and process my refund on duplicates. The lack of response and no action thereof feels like I am been done a favor. Yet a service was offered and I pay for it. I cannot be this frustrated over this especially when you called me as experts and I trusted an upgrade was due as before without issues. But now I feel like I was ****med, 4 months??????even if it is 3 months as the 1st month I had my own conclusions which were confirmed wrong by yourselves, would you call this service. You are making us unreasonable clients when opportunities are given to fix an issue without screaming yet you treat us unfairly