Good luck. The fees must be fair, reasonable, and reflect the actual cost to the company. Their use as a simple profit opportunity is forbidden, but they all do it because the income this generates outweighs the penalties. Sadly this has become more widespread since they've been forced to stop stiffing existing customers with big price hikes after one year.
If they won't fold and won't explain how two minutes work on a keyboard costs them £30 you can raise a complaint online with the FCA, it's quite straightforward. But then I'm a retired git with a lot of pent up anger and time on my hands.