Identity theft

[BENT_8]

So i recieved a letter today from a company called Panthera Finance, they are a debt collection agency and have accused me of owing Telstra nearly $2k.

As i have not had an account with Telstra since 2006 i immediately thought it was a scam.
I googled the company and have read some very nasty things with regards to them.

I decided to ring Telstra to queary it and was told that it was a debt for an account opened in June 2014 and closed in September 2014.
I told them that i hadnt had a Telstra account in that period and asked for the details of the account.
They gave me the mobile number and the billing address and i checked it out and found that the street in question doesnt even exist and the suburb is over the other side of Adelaide from where i have lived for nearly 5 years.
I explained that this wasnt my account because i didnt live there and havent had an account with them for nearly a decade and the woman at Telstra told me that because the debt had been sold to this Panthera mob that i would have to contact them.
So i rang this Panthera mob and spoke to the rudest person i have ever heard, straight away she began talking down and over me and wasnt interested in what i had to say.
She wanted all my details including date of birth and license number and when i wouldnt give them to her she started telling me they were going to start hassling me for the money.
I tried to explain that i dont owe the money but she wouldnt listen and kept going off about wanting my details.
I told her i would be contacting the Police as this is rediculous and she just said go for it.
She kepy getting all flustered and muddled up and said id get a bad mark on my credit file.

So here i am, havent had a Telstra account in nearly a decade, dont live anywhere near the address of the account and am expected to provide all my personal details to some rude collection agent in order to somehow prove my innocence.

I cant believe that they can do this to you, why should i have to prove my innocence to avoid getting a bad mark on my credit file.

Anyone had a similar experience, what do you do.