I have been scamed on my computer and been told by Office of…

Posted by JustAnswer at customer's request) Hello. I would like to request the following Expert Service(s) from you: Live Phone Call.Let me know if you need more information, or send me the service offer(s) so we can proceed.

I am in Victoria. Office of Fair Trading said the company who is demanding $400 from me had their ABN cancelled on the 5th March 2017. I have received a Letter of Demand from a company called Marshall Freeman for $512.81 The company who scammed me was True Blue Software Support Pty Ltd who wanted $400 for installing a fire wall on my computer, (all this started on the 21st of December 2017) I rang them the next day and told them to take the fire wall off my computer as I did not want it. My bank said they did not like the sound of the company and not to pay it. I then went to the Telstra shop who gave me the phone number of True Blue to tell them of the problem but they said I should get an IT specialist I then contacted Telstra Technical Support they said I had been scammed, but I said I had got the phone number from Telstra. They told me to contact Aust Govt Scam Watch, they said I had been scammed and gave me the number for ACCC, I was told to get an Itemised Bill of Account from the debt collector Marshall Freeman and ring The Office of Fair Trading, they gave me the number, the OFT said I needed to ring you and gave me your number. I am not good with IT, I am 79yo and am a carer for my husband who along with a physical disability was diagnosed with bowel cancer last June and had major surgery plus cemo.