Power steering and garage problem

[Ford smax MAX]

Hello. 

I have my 06 smax at the garage.  It was making whining noise when turning. 

They first replaced the power steering pump (£330) but it was still happening so they replaced again (£0) But still happening . Tensioner was also replaced while they had pump out (£30)

Then they took the steering rack to their specialist guy who unblocked something with the piston or something (can't remember exact words they said) who charged £150)

And the noise is still happening. The whole car is due to go to the'specialist' guy Monday so he can hopefully diagnose the fault.

 

I feel sick with worry over this. The costs are at £510 already and the noise is still happening. 

What do I do? I have no option to buy another car and I don't have funds to keep paying for work that's not resolving the original problem.

 

There are a bunch of mechanics working there and they outsourced another mechanic and all dont know what the problem could be. I'd like to add, this garage has a really good reputation and have been going for many years. They aren't cowboys.

Would be greatful if anyone had any constructive advice for my next move. 

 

What would you do if you were me?