Hi we recently had a stair carpet fitted and it looks twisted as in the pattern doesnt run straight it slopes if you see what i mean, everytime i go up the stairs i notice it, the fitter blames the stairs and said there is nothing he can do! any advice please. this is only noticeable on 3 stairs the others arent to bad, do you think he would have to refit the whole carpet or could he just do 3? steps they are in the middle.