Problem with Cancelled Order

I sold a game key 5 days ago but the buyer instantly canceled the order. This should mean that they didn’t receive the code. However, I just sold it today and the new buyer is saying it is redeemed already. Is it possible that the old buyer somehow received the code before canceling? If not, then the new one is lying since I double-checked the code before listing it the first time.

My Code: ZJSKCC
Cancelled Order ID: 5df3288a-36a8-4a7a-a53b-1769efd6515e
New Order ID: e9585bd5-d5a4-4bbb-a6d3-334f49adc00f

If they are saying it is redeemed already then I would ask for proof. A lot of individuals will try to scam on this unfortunately. If you have proof of where you purchased the key from, if they dispute it you can put the proof there and they will also need to provide their proof and then the support staff will go through all the evidence and make their decision.

It would be best to try to work it out with the individual that purchased it, but if the original person cancelled the order, there is no way they received the key as the key is only sent to them after the order has processed.

(I do not work for gameflip, just expressing my opinion)