Lost Cause, please help

I hope someone can help, i have a 2002 range rover vogue, a few weeks ago when i went to start the car it would ot start and the message centre said sport mode, the garage said one of the wires was rubbing so they boxed it in and it was fine for a week, since then it goes back to the garage every week with the same problem, it wont start, the message centre says sports mode and fuse number 5 blows, which is of course the diagnostic fuse. The garage has pulled the seats, dash board and carpet up and checked the wiring but found nothing, the put a new fuse in, it lasts for 1 week then blows, sometimes the message centre says Trans fail safe too, the garage have no idea what to do, its cost me a fortune so far in labour but its sill not fixed. Please please help??????

wow i thought i had problems, i was going to say is your battery ok, but with the fuse blowing it has to be shorting somewhere. Have they checked the fuse box for the usuall problems in engine bay.