UK Car Repair: fuel pump, oil pressure,camshaft sensor and more, fuel pumps, correct time

Question
help please,
Rover 75 saloon 1.8 turbo petrol 52 reg auto

I had booked the car in at a local garage for a missing manifold stud repacement on the exhaust, it had come out and was blowing through the gasket.
On the way to the garage it completely died on me, half tank petrol, turns over and over but will not start!

The nice man at the garage said "fuel pumps gone because no fuel was getting to the engine, he removed a pipe at the back of the engine and showed me no fuel coming through.
So, stud and gasket done, new pump on ( expensive) and it still wont work.
Diagnosis machine said CKD fault error
Next he said Timing belt might be loose, yep it was tightened a bit but still wont fire up, With the air intake pipe off and firing brake fluid cleaner into the carbs! it would start but die again as soon as fuel(B/fluid) had been used.
So then he checks the oil temp sencors as he believes that they control the fuel intake - no joy replaced and still wont start, relays checked and all working fine, reset switch for fuel depressed and reset,
Now he is going to change the camshaft sensor as he beleives that this may have been the original cause for the cut out, 4 days in the garage, i feel a large bill coming on  for a lack of knowledge from a so called expert of 40 years in the trade.
Next stop is, go back to the garage on tuesday and keep my fingers crossed that the camshaft sensor has done the trick, he said "he has ran out of ideas".
what is your advice,
Should i leave it with this private garage guy and pay the bill whether he gets the job done or not or let him keep trying other things. I feel like telling him enoughs enough and get it towed away, saying i dont feel confident in his ability to continue trying.
What are your suggestions?

Answer
This is rather complex so lets deal with things one at a time.  After he replaced the pump did it have fuel delivery? Petrol engines need only fuel, air, and spark at the correct time, to run. The first step in diagnosis is to check these things, if it had no fuel supply the next test should be to see if the pump was getting power! Was it? Next, did it have a spark at the plugs? Most engines have a crankshaft sensor which controls feeds to the ignition and petrol systems, this would be the most likely cause of a total failure of fuel and ignition.