Bajaj Finserv — fresh ecs on every purchase at a store

I could not use my card at rs brothers as i got a message that a fresh ecs mandate is required and my ecs limit is 0.00. I have two loans which got completed just this month with auto debit then how come i have to submit nach form at the branch again and wait for 15 days or more for it to be updated? Is there no online solution where scanned copies can be taken and activation done at the earliest. First of all why should a fresh mandate form be asked each time we are purchasing some thing at stores? I can understand if there were no emis getting deducted in the last three months or if no recent transaction. It was such an embarassment at the counter as we did the shopping and then get to know we have to leave everything