This is BS. The company had a contract to provide a car to the OP at a given price, and didn't contact him until 2 weeks later to claim they couldn't fulfill the contract, thus making him spend a lot more.

The company needs to contact other car companies and provide the OP with a similar car at the agreed upon price.

OP, you didn't mention where your rental is. Please let us know so we can avoid dealing with this location.