Overcharged service and poor service

Last year I received a Chatback message regarding the renewal of my vehicle disc and I thought the process was led by Road Traffic Management Agency. I then though the process would be easy and quick, yes it was quicker however the prices paid was double the amount that I normally pay for my disc renewal.

Seeing that I have paid double the amount double , I then approached RTMC for free renewal because I paid double the amount. Only to find out that Chatback is not an entity of the RTMC. I need my refund because I was charged double and I tried to get its head office line but I'm not winning.

They should remove their payoff line.