Write a Letter to the Bank expressing your displeasure at the continually long lines at its teller counter.

Hello, This is to state that during the past several occasions that I have been into this bank to conduct business, I have been dismayed at the unending lines at the teller windows. It was indeed sheer wastage of time for me to stand in queue and wait for <time you've waited>. Since this is a service industry, I am sure you would agree that making your customers wait over <tolerable time> is not the best way to meet their needs. I would suggest that you look into the matter and see what can be done about shortening the wait time in the teller line. I am sure your customers would appreciate any efforts on your part to improve the service at <name of bank>. Thanking you Regards,