It is rare for a new appliance or piece of electronics not to work "out of the box" perhaps you've been unlucky...
Is there a solution to this?
Yes - exercise your warranty after making sure you've read the operating instructions correctly.
and why should TESCO be selling this useless junk anyway?
Well if it doesn't work then it is useless. Tesco, however, gain nothing by selling you something that doesn't work. Tesco will have wanted it to work almost as much as you do. They need to sell stuff like this to keep their numbers up - sales currently about £1bn per week!
Hope you fell better soon...
Good luck with the warranty claim...
Peccavi
October 2009