How to complain subscription

Hi,
I had a year long sub on photography plan. Received an email to notify of auto renewal on 29th July 21. I cancelled on 13th July 21 . (see screenshot) Subsequently I have been charged and auto renewal proceeded. I have tried live chat, spoke to three representatives and told that if I want to cancel (I am within 14 days of new auto renewal) I will have to pay 50% of sub fees. I was told to provide cancellation email which I did not receive but I DID take a screenshot for exactly these kind of errors. A glitch on their end has obviously occurred. I do not use the service and I don't need it. I was told a manager would call back within 24 hours and I did not hear back. I am in the Uk and the financial ombudsman has advised me to put something in writing as first approach.
However, I cannot find an email address or otherwise. Can someone help. I need a cancellation and refund of payment already taken. I have already had to spent too long on something that I have taken all the steps to cancel. Does anyone have a uk email/address for written communications?

