Outstanding account Ref ***

I had a tracker account with the company. In 2019 I reported to them that I am buying a new vehicle can they please remove the system and install it on the new car I gave details when I am collecting the new car.The lady I spoke to confirmed she has written that and it will be done. On the day of collecting the car I found out nothing was done or no technician ever came, so because the car cannot be released without a tracking device they install the tracking device from the other company. When home I phoned them telling what happened. As I was happy with their system and still need their service I insisted that they have to reinstall so the technician was sent and install the device on the new car.The sad part now is receiving messages that say I have outstanding amount to pay, as far as I know I don't owe them the account is up to date as we speak. I have been in contact with them explaining and they can even retrieve the call as they always say it is recorded and they don't retrieve say they can't find it.I feel that is unfair as I did report on time that I am buying a new car and explained what I need to be done, they failed to do their job,now I must pay .My question is What I am paying for?maybe Helopeter can assist to get me clarity which account is outstanding as per my explanation.