Do I have to pay any fees if I froze my gym membership account for 6 months but they billed to the wrong account and never contacted me?

The contract with the gym membership governs this situation.  if there is a clause that permits you to freeze the acount and you complied with the provision, then you did what you were supposed to do under the contract.  if the gym simpy made a mistake as to the billing, then the gym should recognize this as a mistake and correct the billing.  I am not sure why the gym was billing a wrong account number.  if you have one account number and you froze the account i am not sure how the gym was billing you.  if the gym simply failed to recognize the fact that you froze the account, i suggest that you show them all written communication regarding the frezing of your account and a hospital bill showing that you gave birth.  the gym should fix this.  I would not pay the fees and ask to speak to a manager.  if you are not making progress, hire a lawyer to help you here as the gym should not be able to unjustly enrich itself it you complied with the terms of the contract - i.e. freezing the account.