Is the mobile banking service contract and ATM card compatible with Sharia, knowing that the deducted amount is not mentioned in the contract, and that the client agrees to the fees determined by the bank and authorizes the bank to deduct them?

What is considered is knowledge of the fee. If it is known by common practice, or by the client asking the employee about it, then this indicates that these are known and specified fees. In this case, there is no harm in engaging in that transaction with the bank and accepting the service, because knowledge of the fee is a condition in the leasing contract. An exception to this is what is determined by common practice, such as riding cars and airplanes, in which case common practice is referred to, for "what is known by common practice is like what is stipulated by condition."