Record all calls. During coming call narrate that on dated.................time.........from phone number................Mr/Ms...............called and were told that..................and were instructed not to make any phone call again................but the harassment, and nuisance is not stopped..................and you shall be contrained to lodge police/criminal complaint.
Submit a terse representation to local BM under proepr acknowledgment and demand to beg apology in writing and stop the calls and claim damages.
Lodge police complaint.
Escalate with acknowledged copy and call recrdings to MD,Chairperson Chanda Kochar and still if required approach police,court of law thru your able lawyer.
There are many threads on M/s ICICI Bank and recovery agents at LCI...............