Having easily achieved the government mpg figures for various vehicles from new (petrol and diesel small and large), I was confident that I could expect the the combined 80.7 mpg figure promoted for the SEAT Ibiza Ecomotive I purchased on the 6th December 2010. My journeys to date have all been medium to long - combined/extra urban, driver only, no extra load, low revs and speed, running in the engine as per the manufacturer's manual and changing gear as indicated for best fuel economy.

...However the highest figure achieved to date is 51 mpg. I have been in contact with both the Retailer (SEAT West London) and SEAT UK on several occasions with the vehicle receiving a full diagnostic check although no fault identified. Regretfully their responses in attempting to justify the performance issue has been less than satisfactory and insist the vehicle is fine. I have stated the Sale of Goods Act 1979 and demanded a like for like replacement or full refund, although they appear to have washed their hands of all responsibility for their product.

What can you advise is the best course of action for me to take from here?