2013 Model S A/C cooling issue

[UTArch]

Just before cool weather arrived, the A/C compressor in my 2013 Model S stopped working (ie. no cooling of the air, system only blows ambient temp air). I took it to the Tesla Service center here in Austin on Fri. Nov. 17 at about 10:00 am. On Monday, Nov. 20 I received a repair estimate through the app of approx. $950, which I approved so that repairs could begin. Two days later on Weds. Nov. 22 I received a revised estimate (again through the app) of approx. $1680 which I also approved. This morning Sat. Nov.25, eight days after I dropped off my car, I received another revised estimate (3rd estimate) through the app of approx. $6475. Unless I approve THIS estimate, they will not "continue"to diagnose the problem. They stressed that this estimate is a "worst case scenario" estimate BUT they said that with both previous estimates as well. Here's what bothers me -- they have had my car for 8 days, and the only progress has been to determine that there are "electrical/wiring"issues causing the problem. There is no guarantee that there will not be a 4th, 5th or even 6th revised estimate. I have not approved the last estimate and I don't know what to do. Does anyone know of any options I might have besides giving them unlimited time and budget to solve the problem?