Audi - Qualitat

I had a problem.
The Audi Allroad was not running properly.
A 'technician' said it was a Torque converter failure.
A new one will cost $6000.
So I said naively,  fix it.
Have not seen the replaced TC..
After repair apparently the same 'technician' test drove it again and claimed destroyed a timing chain.
That will cost $3000 he said.
So naively I said fix it.
Then I was harassed to come and
pay the $10800 bill and take it away .
So I  took delivery and immediately recognized similar mechanical  issues.
It was towed back to Qualitat.
This time when a mechanic checked it, found a coil was faulty.
He told me that causes the symptoms I experienced.
Another week of work he said.
Qualitat had already had the car for over a month.
The technician estimated $6000 for the Torque converter and than after the test drive $3000 for the timing chain that was damaged while in their shop.
Then surprise surprise I was charged $4000 for TC not $6000 and $6000 to replace the timing chain not $3000 then a further $400 for one engine mount undiagnosed, and that was after a $2000 labour discount apparently. 
He seemed to be oblivious to the wildly different pricing and could offer no explanation.
This is unacceptable in this age of knowing the price of everything and paying for it before you get it with no recourse.
It's all about Trust I guess !
So the diagnosed fault that is still there and causing similar symptoms is an electrical coil on cylinder 8.
Despite a new Torque converter (oh it happens a lot) and a timing chain (could happen any time) the Audi V8  motor had done only 140,000 km !
Well that is the latest "problem" that just has to be fixed, well of course it does,  because after $10800 it still is undriveable
....and the same issues seem to remain.
Of course it could all be true and the work was needed and done properly.. truly it could be !
Or it could be Audi are a heap of unreliable  expensive junk !
But there is more,I was told the 'missing' was a coil on cylinder  8.
Well it seems it wasn't that at all, it was the senders so all 8 were replaced.  Guess what..too embarrassed to charge.
Still runs like a goat.
Then had to replace the brake pads...undiagnosed after two mo the and numerous test drives.
For comfort and reliability I prefer my 1993 XJ6 it cost $5000 six years ago and nothing since.
Qualitat....only if you are not risk averse. Well maybe they are honest and competent  and I was there for a bad two months.