"Horn of the Vastiri" quest item vanished, game progress halted.

I think I've encountered a bug. NEED HELP!

I'm a PSN player, I encountered a bug after creating the "Horn of the Vastiri" in Act 5 around 7:40 am ET on December 21st. When I tried to transmit to the "Temple of Chaos" from Act 3 for a trial, I accidentally stored the horn in my currency stash, and it vanished. I can't find it anywhere. The game plot is now stuck. Has anyone else experienced this issue?