Worst company ever established, terrible service provider with no integrity!

I have had a tracking unit with them since 2018, I bought a new car in 2021 and paid a fee to transfer my unit from one vehicle to the next. I since sold that vehicle and notified them per email in November last year to cancel the unit, I made numerous phone calls and this was simply never done. I continued to send emails, they continued to debit my account. This forced me to put a debit order stop and they then started threatening me to hand me over for non-payment. Eventually I received an email this month confirming my account has been cancelled and they now want a cancellation fee which they claimed is for the 36-month contract, I then asked for proof of me agreeing to this contract since I had the same unit and account since 2018 so this should be on a month to month, needless to say I am still waiting for a voice recording or signed contract of this. They have zero integrity and the service they provide is absolutely horrific! Do not make use of NETSTAR you will only regret it!