Or monthly SEPA transfers. That I can set and revoke at will. I wish that there was an error-proof (on my side) way to set the exact amount though. And a range

Or monthly SEPA transfers. That I can set and revoke at will. I wish that there was an error-proof (on my side) way to set the exact amount though. And a range acceptable for the company for what day of the month to do the transfer. I don't understand why I would need to go through anyone else for this than my bank(s) ?