RBL Bank Same Issue — credit card follow up

It didn't look like the back is taking any steps to solve the issue. What next to be done to get rid of this nuisance. Please advice
The bank interest gets back saying we have looked into it and say since it's overdue from our end or christy cats people call. But

When they have a time limit why do they call bloody n number of times for reminders
And top of it there's is also a message be on a daily basis
I think rbl bank is new to they industry and doesnt know to maintain customers very intact.
If this is going to be their modus operandi then they're will be a real dearth in their customer database i mean business like me will surely surrender their cards. Better let them wake up