FIX THE UNIT AND PAY MY BANK ACCOUNT FEES

I have been a Cartrack client for more than 10 years without any challenges. Last year I contacted Cartrack due to a new Unit that should be installed on my car as I was told by a 3rd party that the Unit was only valid for 3yrs and I had the unit for more than 7 yrs which means the Agreement is non-existing and Cartrack never mentioned this to me, the Consultant confirmed this with me. I was referred to a local branch for installation on 03/07/2020. The new unit worked for a few weeks and not it is not working, I have called I don't know how many times explaining the problem. Technical dept called me and we made appointment to fix the Unit on 12/07/2021. No one to this day 27/07/2021 called and the unit is still not working. To my surprise, this morning I received an SMS from PERUMAL ATTORNEYS stating that I have been issued with SUMMONS. I have been paying my account even if the Unit was not working until December. I then said they should CREDIT MY ACCOUNT, take the money for the unit that was not working from July 2020 until December 2020 and use it to pay for the unit on the other car. I am being debited daily, CALLED NON-STOP which is so *******, now my Bank Account is on a huge debit balance, so where do I get the money to pay Cartrack as I now have to pay the bank FOR UNPAID DEBIT ORDERS (UNIT NOT WORKING) I complained about this but no one listens. THIS IS SO UNPROFESSIONAL AND HOW MUCH I WISH I SWITCHED TO THE OTHER COMPANY THAT CALLED ME, YOH!!!!!