Spaying should/does include the uterus.
Who did the spay? Did you see the incision site?
If it was done before you got her, there might have been a mixup in the records. Contact the rescue group.
If it was done by your vet, a previous one I assume, I would talk to them.
At the least, you should get you money back.
Once all of the facts are in, you may want to consider reporting it to the State Vet Board, dependng on whether you think it was intential (as in fraud) or a unintended error (don't report).