Unable to refund buyer on ebay

[zalism]

Hello I will start by saying this: I'm 15 and recently sold an item on ebay but cancelled it because they payed in paypal and I couldnt accept the money because they needed my social security number which I did not know was a thing because it was my first time selling on ebay and using paypal.  but the cancellation had an error and I had to refund them manually on paypal. I couldnt because I didnt have the money on my account anymore (cant explain) 

Then he emailed me saying to refund him. We had a whole convo on how I can repay but he didnt bother. Now ebay is saying to refund. It's only $1.23!! what happens if I don't?