Tax Relax, ****** rubbish

I've been paying these people for years more than 500 a month, I receive one email a year telling me what i need to submit but no follow up, nothing. When call they say they'll call me back, this was now weeks ago. Their service is terrible. I've tried to cancel with the, and also no response. I'm pretty sure trying to get my money back for the nothing they've done would also be useless.