The boot on my 407 2,0 HDi Saloon wont open, how can I fix the problem !!?

Please help !! it's been 3 wks now, car was fine then one morning went to open car with remote & nothing, changed battery, re-programed remote fob, still nothing, on unlocking car manually found boot won't open, everything else opens except boot which should open manually when you unlock.

Had to go in through backseat to open boot, checked boot wiring, fuses, all ok. Took it to my garage, they checked boot wiring, wire housing on the left for breaks/cuts nothing. They took out the inside boot lock swich not the outside button & tested, test concluded that the swich was faulty because the power was insufficiant for the switch to release/open the boot or something like that !!, anyway bought new boot lock, £40.00 fitted, still no joy.

Garage say it must be central locking, need to go to Peugeot or get electrician to check all the wiring, £50.00 an hour, open ended.

Please help, remote wont work, boot still won't open, driving me mad !!!!