HDFC Bank — Non stop calls to take loan from hdfc

Address:

Anakaputhur, Chennai

Its almost a year now hdfc telecallers continues to call me asking to take loan with them. I have explained multiple times that I am in no need of one. But these guys don't stop. When I ask them to stop calling, one of the lady is supercool asking me to keep my no in DND, which is already registered under DND as per my service provider. I have also raised complaints with airtel on this by sharing the numbers. But its all useless. I work in odd shift timings and these guys always find the exact time I sleep and call me. I marked most of their numbers as spam still I get calls. What can be done? Should I raise it with the local police? Please advise this is becoming worse now ..