If you do not agree with the amount that has been debited by your landlord you can do a number of things.
First of all, it is useful to log in to your account as tenant and see why the amount charged is different than you expected. Perhaps there are one-time costs charged, or a rent increase has been implemented.
If you still don't agree it is wise to contact your landlord and ask for an explanation. If this does not lead to a solution you can decide to reverse the amount from your own bank. The amount will then be refunded to your account within 2 working days.
Please note that doing so does not remove the obligation to pay the rent. For further questions on this subject, please contact Bidly at firstname.lastname@example.org.