@Mark ********
Bank branches in different provinces are definitely not different companies. Thailand has only one banking regulator, and there is no separate licensing by the provinces. The idiotic fees for transactions in other provinces are often listed on their fee schedules as "communication fees", and are an archaic leftover from the days - obviously long, long past - when they would have to send a telex to the account-holding branch to pass on the transaction information. This clearly makes no sense in the modern era, but they hang onto it because hey, why not make some extra money if you can?
Oh, and CDM is "cash deposit machine".