Crown placed on the wrong tooth!

[tczomn]

My dentist infrormed me that I was in need of several crowns. As I do not have an unlimited supply of money I asked him to tell me which was most important. The one he indicated required a crown lengthening done first. After that miserable experience I returned to my dentist to get my crown. When I got home after the appointment I looked in my mouth and realized that he did not do the prep work for the crown on the correct tooth. How long can my other tooth last after lengthening without a crown? Should he do it for free now? Help!