u/Alpha2354

Hi all, I’m very new to selling on eBay, just use it occasionally. I have just sold an iPad Pro for £700, after dropping it off to my local post office I messaged the buyer to let them know it’s been sent and to thank them for buying it. They replied within 5 minutes saying can they cancel the order as it’s too expensive and they shouldn’t have bought it. Am I going to have issues with this? Thanks for any help