I haven't had this happen. When the repoman took something, it was gone and I was able to replace it when I was able to.
So, it sounds like something is off. Not sure what but I can offer you a couple of suggestions though.
Since it's over 8 hours since you posted, you've probably already shut the game down. So that might fix it when you next load the game and play that lot. If you haven't quit the game, though try saving and quitting the game and restarting it. Before you restart, you can also delete the localthumbcache file. That tends to fix some things too. Don't worry, the game will make a new one the next time you start. Only thing you will see is that all the thumbnails take a few seconds to load since they are being created again by the game.
Another thing you can try if that doesn't work is to save the lot to your library, bulldoze the lot and replace it with the library copy. Make sure you bulldoze. Don't just load the library copy and replace. Bulldoze the lot then replace it with the copy. You might lose the credit for your collections so before you save the lot to your library, put all the collectables you have in a sim's inventory to avoid that. (You could make the copy first though, then put the collectibles in a sim's inventory, and when the lot is replaced you have 2 of everything so up to you.)
Hope this helps.
