to much petrol

hello everybody been a while since i posted anything on here thanks to mark fixing the last problem, but im here with this now, the petrol consumption is through the roof, i got only 62 miles out of £15 fuel, that was a mixture of some motorway driving (about 20 miles ) but mainly short stop start journeys. i put in another 10 pound petty and done only 10 miles and its almost touching red again, when i put it in it was just under the 1st white marker, any suggestions, had new spark plugs fitted and as had a new lambda sensor. your help would be appreciated.