CreditMantri — daily calls

Earlier i shared my number with credit mantri to check on my cibil and to seek help clearing the amount.
Later i decided not to go with the services. I requested them not to call. But on daily basis i recieve 3 to 5 calls and i am annoyed. It has been one year since i am requesting them not to call, but they daily call from unknown numbers. I feel this is marketing harrassment. Shall i check with my lawyer to collect call recordings, evidences and file a case, or you will be generous to help me here?.

Thanks,
Vikas verma
[protected]@gmail.com my email id.