Product: Money transfer, virtual currency, or money service

I received a branded email from PayPal saying that I had transferred funds to purchase XXXX and in order to dispute the claim I called the customer service number in the email. When I called, the representative pretending to be associated with Paypal/XXXX said that my security had been breached and that he needed to run a security check in order to cancel the transaction. When doing that he said that my XXXX address had been compromised and that there was suspicious activity dating back to the beginning of the month including illegal purchases in several other countries. Insisting that he was associated with PayPal ( an accredited bank ), he said that in order to cancel these and ensure new security we needed to go through a process with PayPal, XXXX, and Venmo since they're owned by PayPal. I was told that because I had not done an identity verification with PayPal, that was why I had been hacked. He had me download an app on my phone so that he could guide me through the process by seeing what was on my screen, including personal information, account details, my ID, passwords, and the amount of money in my bank accounts. 

He said that we needed to transfer money to his Supervisor of the PayPal Security Branch, and insisted that the money was coming from him as a PayPal representative and that it would not be coming out of my account. It did, in fact, come out of my account. Through the XXXX money transfer app, he had me send {$1800.00} to the supervisor in order to get account verification and justified the amount by explaining it as a way of validating the account limit so that if someone in the future tried to hack or breach that limit, PayPal ( him ) would have already put some measures in place to prevent it. After that transaction went through ( instantly ) he said we had to do the same thing through venmo and had to send the same amount of money to someone in my venmo transaction history. ( She, thankfully, was able to send the funds back to me. ) He also called her pretending to be Venmo/PayPal support and tried to go through this same process with her saying that she needed to send money to a random person on Venmo in order to move through this process. 

Next, when I began to insist that I needed to be refunded for the initial transaction on XXXX, the PayPal representative transferred me to another branch for refunds. But first, before getting to the final refund step, insisted that I needed to complete the internet security steps in the process which involved driving to a PayPal XXXX XXXX in a warehouse 200 miles away. I insisted that I would not be doing so and said we needed to skip that step in the process and refund my money from the XXXX transfer. He refused, said that there was a process in place for a reason, said it would be impossible and refused to go any further if I would not comply with this step. And now through this fraudulent scam, Ive lost {$1800.00}. 

I tried taking steps through both XXXX and XXXX but neither was willing to help. XXXX said theres nothing they can do and XXXX says that they can't get involved in disputes between senders and recipients. Please advise on how I can further dispute this transaction and regain my money.