Netstar, Only Good for Tracking Debit Orders!

Netstar are quick to communicate with you when they need the business (and that's it) but absolutely zero communication when it comes to a customer cancelling their account (and unit). 4 months after initially making contact with Netstar to cancel my account and each month since then they're still (trying to) debit my account. I've emailed Netstar repeatedly during this 4-month period and not a single acknowledgement. It certainly makes me question their overall priorities including their main purpose of tracking and responding to an emergency, since they can't acknowledge this simple request (instruction).