If dealer withheld valuable info to my decision making process is order to make my repair bill costly can i dispute the bill?

A dealer mechanic advise me that he was 90% sure a $700 repair will fix the problem of my car shutting off. after doing this repair they told me that they were able to know for sure what the real cause of the problem was and it would be an additional $267 to fix a bad sensor. They said the knew about the bad sensor before but wanted to make sure it was really bad by replaying a battery terminal for $700. I had a different mechanic replace the sensor, it did fix the problem, and was told it was a common problem with this model. I asked about the battery terminal and showed them the old part, they advised me that the battery terminal was not in the best condition but it would not have been causing the problems I was having. I was never told about bad sensor until after I paid the $700.