406 wont start when cold

[channon]

friday morning was the coldest morning yet windscreen was frosted over this time the car was impossible to start, killed the battery, even ran it down the hill to bump start it no good had to wait on a friend with jump leads eventually it went ,took it to a diferent garrage who said glow plugs , i told him they had been changed he tested them only two where working i got 4 plugs £9 each £20 to fit them and today at long last first turn she started.Thanx to everyone for their help, im off for a refund of my usual mechanic who normally does a good job