I don’t know if this has been reported or anything, but it seems that latency (either on ROBLOX’s end or locally, I’m guessing) seems to cause ROBUX and Tix used for MarketplaceService transactions to get ‘eaten’. By ‘eaten’, I mean that the robux and tix will be gone from the account and the transaction will appear in their Transactions page, but they will not get whatever they purchased.
One symptom of this is ‘infinitely loading Purchasing… MarketplaceService GUI’
On rare occasions I do get reports from my players saying “I paid for X developer product but didn’t receive anything!” I’ve never experienced it or witnessed it myself, though, and I don’t know if they end up receiving it after rejoining the game.
[size=2](Or whether they’re just lying to me to try and get free cash…)[/size]
I run into this occasionally (less and less as of late). I’ve never seen it happen myself, and given how far and few between it occurs I’ve left it alone.