I used these over 10 years ago and it was fine then they claimed a percentage automatically on a future refund so I rang to state I did not want this anymore, they were nice about it and agreed to stop future claims however, from recently logging into government gateway i have found out they are still recieveing mail on my tax affairs. This is not authorised, I have submitted a contact form after which I will put in a subject access request and see how I can escalate further to stop them.