Any way to contact people who bought from you through async.

Simply put was dumping a bunch of maps that i didnt want for 1 chisel each. Switched another item to 250c and then went back to maps. Didnt realise i set some maps to 250c (because inherited price thingy) before the game locked the items at that price. Quickly renamed the tab like "careful prices are wrong" and hoped no-one would buy. Sadly someone accidentally bought 2 of the 250c ones and i feel terrible.

Question arose, is there a way to track the buyer down so i can return their chaos orbs. Preferably through an actual system.

No. If you see the person buy the map you can try whispering their IGN that is visible, or just switching to local chat and calling out, but the log does not provide that info.