Netstar insists I pay for a service after cancelling my contract: Using Creditworx to harass me.

Where do we report Netstar and their harassment of customers by Creditworx? I had a three year contract with them, and when the contract came to an end the agreement was on a month to month basis.

I cancelled the month to month, but they still billed me and insist that I pay the two months that they billed me, despite me cancelling. Everyday, the agents at Creditworx harass me. They even listed me, fortunately I'm a Transunion client, so alerted them and they removed this listing as there was no evidence of me owing them. Can someone investigate Netstar and their shady dealings?

I'm not the only one who is complaining about this harassment on this site, and the complaints are similar. It's also clear that they're taking advantage of us as consumers. I'm sick of the daily harassment.