Spinvox fraud

Tuesday

Some years ago, I signed up to Spinvox (it converts voicemail messages into texts). I used it for a couple of years and then about 3 years ago I cancelled it.. Today, I received a text from Spinvox telling me they have billed me a month's fee. I rang & complained but was told my account was still active and they are refusing to refund my money. But I don't get the Spinvox service - and haven't had it for years - so how can they bill me?
Anyone else having this problem? I have emailed them and demanded a refund. If I don't get it I will report them to Trading Standards.

Halloway

How have you been billed? Credit card, debit card etc? Sounds like a ripe candidate for a chargeback.

Tuesday

It's billed to my mobile provider so I'll have to pay it via my phone bill.