This has been happening a lot recently between me and my friends, specifically SilverCobra, HiImJustin, and me. HiImJustin wanted to sell me 24 ore, but I declined the trade offer. However, after I declined the offer he didn't receive his ore back. I deleted my message to see if it would go back, and he did the same, however neither of us recived another message saying we got our ore back or got the ore back in general. Just wanted see if anyone knew what was going on! 

Thanks in advance, wether that would be fixing the bug, or telling me how to prevent it.

Go to Item sales, there's a tab with My Auctions and Exchanges. Private sales should be visible there. If they aren't then it's a real bug.

If they are visible, there's a button to cancel.

Thank you, I just checked and I had no idea I could do this! I feel like I should've known this...anywho, thanks a bunch!