Refunding a buyer after 6 months because of unauthorised payment

[Albus12345]

I have just been told I have to pay back a buyer £285.50 because they didn't authorise the payment back in november 2017. However, I sent the item by special delivery. As it was back in november  I do not have the tracking number. I also don't have £285.50 in my bank. 
I am seriously freaking out because I don't know what to do? I have tried to call paypal and eBay with no luck actually speaking to a human. 

Does anyone have any advice? I thought I paid fees so that I would be protected from this!!!! Help me!!!

[kernowlass]

@Albus12345

An unauthorised transaction means that an account holders Paypal account was hacked and used without their consent by your ?buyer.
If Paypal check IP addresses etc and find in favour of the account holder then of course they are reimbursed.

However you would not lose out either as long as you met ALL the requirements of seller protection, so your best bet is to go and read up on it to make sure you were covered. If you think that you were then..............

Click on the words "Help / Contact" at the bottom of paypals pages and use the phone option in the blue band at the top OR very bottom of page dependent on what country you are in. Log in and get the code.
When you get through don't select any options just hang on till you get transfered to an agent OR just say the word 'Agent'".
In the UK its free from any landline phone.