i explored this issue a few years back. there seems to not be many options for legal rep, they are federally protected buildings run by locals who receive orders/policies from managers sometimes states apart. communication about standards, or changing standards is easily not returned.

i do most of my banking on line (p/c).

if a bank gives you hassle for using "drive through", mention your concerns and move on to a bank that accepts you.
i have brought my bike into the lobby after refusal of sevice in drive-through, got banking done that way. do what you need to do!