Unreasonable administration fee and misleading information

I hold 3 different policies with Liberty (home, motorbike, car) and I tried to change my address 20 days before the expiration of my car policy in order to renew it and I got charged an unreasonable administration fee of 30€. The worst thing is that the customer support agent who started to do this change on my account didn't let me know that in advance, because if she has tried to do this I would let my policy to expire in 18 days and then create a new one with my new address and no administrative fee.
I felt that I was trapped to do so, as the whole process was very misleading both from their website and phone call.

I am now searching to change all of my policies with them and go to a different more customer fair company if they won't take back this charge.

This is totally unacceptable. They are trying to trick their customer for 30€ where my annual premium are close to 2k for all of my policies.