Identity theft query

I lost my ID in July 2017 and it came to my attention in January 2018 that someone took out a loan on Loan match with my ID that i am unaware off.i have tried numerous times to contact Lifestyle legal since they have been sending me letters of demand threatening to garnish me regarding the loan that i am unaware off.i even went as far as emailing them a copy of an affidavit from SAPS as proof of this identity theft and explaining what has happened.i have made numerous phone calls to them without a response from them.this is so frustrating as it will tarnish my credit record and whats worse is that the company fails to respond to my coomunication and its been sic months with no response or way forward from Life Style Legal Pty Ltd.