The most common way people accidentally delete their PWs is by trying to resize their claim. If a PW location is unclaimed at any point, the PW is deleted. Sometimes, a player will delete their claim, then create a larger claim in its place. This deletes any PWs within the claim.
What you need to do instead is use your claim tool to grab and move the corner of your claim to resize it. PWs are preserved this way.
I assume your PW was not deleted by staff. If it was, you'd also be punished for whatever rule the PW violated (e.g. inappropriate PW name or TP trapping).