2002 Other Citroen Models Please help!

2002 Other Citroen Models 4 cyl Manual 58000 miles

I had a car accident in dec 2009 (damage to the front left side). The insurance "fixed" it & got it back to me early jan 2010. Within days I noticed that everytime the steering wheel turned the front wheels knocked. I sent the car back in for repair to which they replaced the steering rack/mount. I only got my car back yesterday (some 4 months after they originally fixed the car!) And can STILL hear knocking on the left wheel. I've spoken with the garage today who said that their not sure if they can now fix it due to insurance regulations - what does this mean! Where do I stand? Surely if the car was fixed properly in the first place we wouldnt be in this situation! Can they refuse to fix it & if so, is the car dangerous to drive? Will it fail the MOT in june? HELP!