Don’t use Netstar !!!

I started using Netstar in 2020 and cancelled my account last year September but they still debited my account.when they debit my account I would reverse the money,now I’m told I owe 2K because I didn’t pay my account since last year October.How because I cancelled my subscription? Now this is affecting my credit record !!! I regret the day I subscribed with Netstar,WORST car tracking company EVER!!!