I had unclaimed my plot to do some work, and in two mesely seconds, @MineAidan07 had claimed it. If you need the plot ID, I can give that to you: 89;-92 Instant TP command (Opped players only) : tp @p 5042 65 -5286
Just ask MineAidan to give it back. If not, tell him that you unclaimed it so you could "work" (please explain).
I would do as LuckyLeo suggested and convince MineAidan to return your plot to you. Consider sending him a PM on the forums or contacting him ingame. If you have issues trying to talk to him, let one of the staff members know and they can have a word with him. For future reference, I highly recommend keeping your plot claimed at all times as losing it due to unclaiming is - while an understandable accident - entirely your fault. I'm kind of curious as to what 'work' is, if you could explain that we might be able to give you better advice.