I want to make a formal complaint

I want to make a formal complaint. 

I signed up to a trial and when I didn't use it or decide I wouldn't use it as much as I think I would, I was then misled to signing up to 2 extra months at a discounted price thinking it was a part of the trial and I could cancel at the end if I still didn't use it.

In the end I haven't used it since so I've wasted my money. When I've tried to cancel I've been told I need to pay £86 cancellation fee. 

Online chat is useless, the person I spoke to was rude telling me it was made clear to me at the time. How exactly does he know thst unless he was there when I sign up?! 

I feel like adobe are trying to trap people in an annual subscription when all they want to do is trial and cancel if it's not suitable.

Then when I tried to ask someone else for the complaints email or speak to a manager, they transferred me the same person who was rude to me. 

Absolutely appalling customer service.