The wife's Citreon C4 failed it's MOT when done at National Tyres cos Front Pad's less that 1.5mm. Took it to our garage that we alway's use, job done but they advised that we had a worn Drop Link. We had heard a slight knocking noise but assumed as not picked up on MOT, nothing serious. Apparently a worn Drop Link, should be a fail. Re-test done yesterday at the same place, took 1/2 hr, still not picked up worn Drop Link. Should we complain?