Who's right? Seller or buyer?

[craftsandcreations2015]

I sold a switch as spares or repairs, posted, received the money. The buyer contacted me saying there is a parental lock, I've sent multiple codes and tried to figure it out, advised that there are videos on YouTube to help, now the buyer is saying they're going to request a refund. But it was sold as not working. Who's right here? 

[tobiasd4]

Does not matter who is right.

If buyer opens item not as described case, ebay allow it.

Issue returns label and refund in full on return.