I vaguely recall seeing a Thanachart bank there years ago. Google says there's a bank next to the Big C but their street view shows a restaurant.

 

Is there a Thanachart in that area? If not I suspect the Central Festival location is closest.

Nothing there but there is a huge branch at soi 11 2nd rd a few minutes past mikes mall on the way to central. Or get the baht bus soi buakhao and walk down soi 11 to second rd