Extremely frustrating experience

I'm getting an email saying they are collection debt on behalf of a business whom billed me 10 months worth of services I never used, because I didn't cancel the account which I didn't even know to do. Fair enough, I try and resolve the debt by trying to reach out for a debit order. I've tried ALL emails I've found linked to their business, plus I've rep**** to ALL emails they have sent to me, only to have it bounced again and again. This is the most frustrating experience I have ever had with regards to such a business. Yes, I have also called, trying to resolve the issue, only to be put through to a phone that was never answered.