You are not a guarantor. Police can not be outside your residence. CC dues are civil liability and company can proceed to recover dues from your friend.
The person coercing you on phone is fake and is a recovery agency. The statements being given to you on phone are a standard draft which all in this trade use e.g CC companies, telecom companies etc.
The reference may be approached to know latest whereabouts of CC member or to persuade him to meet CC Company and settle dues.
Your may record the telephone calls and lodge a police complaint with O/o Police Commissioner and SHO making the local BM of the company a party, and obtain complaint number on your copy. If you can apply your resources in each O/o SP/Police Commissioner there are police employees who can find the address where the phone is located by one click of the mouse.
RBI guidelines on recovery are self explanatory and obviously the CC Company is violating the guidelines.
Kindly look into the attachments.If you are not able to handle the matter approach a competent and experienced lawyer and your lawyer shqll issue a legal notice to the MD/Chairman of the bank, and local BM demanding to supply the reason of such calls , address of recovery agency and its RBI registration number, and reason why your contact details are passed on to this agency for recovery from you and threat you.