Thankyou for the responses regarding the clunking noise. Yes it's just one clunk and it one seems to happen only happen sometimes, but it's not the most pleasant noise to hear when breaking.
It happens mostly when going from reverse, breaking, then going forward and breaking, then a clunk. Sounds like its coming from the rear.
Started to worry about how serious it is. I think the big mistake I made was taking it to kwik fit to sort out the brakes.