Disgusted with Netstar.

I took out a contract for a car tracking device with Netstar in 2021, the 36 months agreement lapsed in December 2024, in March 2025 I contacted them that I need to terminate my services with them with no success as my e mails were not responded to, they kept on debiting from my account but there were no funds which caused my account to run on negative, I contacted them again in May and the person who responded said the cancellation process will take 30 days, but in June I got an e mail from Nimble that I have been handed over, I explained my issue to them and provided our email communication then Nimble sente back to Netstar as they said they couldn't assist further...on the 15 the of the same month they attempted to debit again with no success, now I have received a statement from them stating the amount that they claim I owe... someone is not doing their job there, as no one is fruitfully assisting me, I don't understand why am I being forced to keep services that I no longer need.