Cost for changing my surname

I really don't understand how can i have two accounts for same address when i requested to change my surname, how can they charge me for admin fee for just changing my surname, my account is a mess. I complained several times but they keep on saying they will get back to me, but instead they debit from my bank account. I don't even have a year with this company but they already broken my trust, they aren't capable of securing my home