My fiance's 2015 Jeep Wrangler has been at a Jeep dealership for the past nine days. It was brought in for extended cranking before it started and stalling at idle. We briefed the service advisor of an independent shop already have changed the 6 plugs with NGK iridiums, replaced the crank sensor and the cam sensor with no improvement. The dealership service advisor called my fiance the first day it was dropped off informing her that it still has the factory original crank sensor the independent shop charged fiance $171 to replace. Also the dealership reported that the crankshaft sensor wires were tampered with. Yesteday the dealership reported the iridium plugs are shot aand likely the cause of the misfires. The coils checked out okay. The dealership will be handing over all the original worn out parts to us when the Jeep is ready to be picked up. What would be the best way to approach the independent shop that didn't seem to do any of the repairs they agreed to and billed us for? My fiance missed over a week of work already since her Wrangler is a rare right hand drive used for her 96 miles rural mail route for the post office. She had a massive amount of misfiring and stalling for a couple weeks while we relied on the independent shop to fix the Jeep. Would that have taken the life out of the catalytic converters? She's stressed to tears over this. I'd like to help prevent this from happening to other customers as well as recover the hundreds of dollars she payed the independent shop. Thank you in advance for your advice.