Customer saying item not arrived but I sent. What can I do?

[Sbranny81]

Hello, I sold something on Facebook Marketplace and gave the buyer the option to have 2nd class post included or to pay extra for recorded. she chose 2nd class so I obliged. I posted it, along with several other items all of which reached their destination but this buyer sent me an angry message to say it hasn't arrived and she will be demanding a refund. Where do I stand as I did give her the options and I know I sent it. I'm concerned as I've had it happen before where people do receive items but claim they didn't to get the money back. Can paypal refund her without my say-so? 

[kernowlass]

@Sbranny81 

In the event of an item not received dispute the only way paypal can know if the item was received or not is by the seller providing a tracking number.

You don't have to send trackable but if you don't then you would lose any dispute for non receipt of item.

If you refused to refund and there were no funds in your paypal balance for paypal to access then they would put your account into negative until you paid them back again.

To be honest I find it odd that you don't want to refund a buyer that didn't receive their item, if you ordered something from Amazon or anywhere and didn't receive it then would you not want a refund or would you be happy if they said 'sorry we posted it so no refund?'