Help Needed With C Max Problem

My Cmax (2004 Focus C Max 1.8 Duratec Petrol) is causing me problems again and I need some help!!!

I had problems a while back with stalling when approaching junctions etc which was resolved with a throttle body clean. I then started getting haning revs between gear changes but only about a minute after the car had been started. In the first minute of starting the car is fine and after about about 5 minutes of hanging revs the car goes back to normal.

I took it to the garage where they said I required a new Throttle position sensor and throttle body which I had fitted. This made the problem worse in that the revs would now not hang but steadily increase if depressing the clutch whilst driving. It also developed a judder when switching the engine off and poor MPG (struggling to get 300 miles out a tank). The rev problems again only happen about a minute after starting and last for 5 minutes.

I took it back to the garage where they re calibrated the throttle body and updated software etc, the revs no longer increase when despressing the clutch whilst driving they just hand at the point the revs were at when in gear.

I just dont know what to do now!

To outline my current problems: -

1, A minute after driving from a cold start the revs hang when changing gear, this lasts about 5 minutes and it then appears to go back to normal. The first minute of driving from cold start everything is fine. If starting the car from a warm start there are no problems.

2, When approaching a junction etc (after the car has stopped the idle hand) the revs drop to the first line above 1000rpm until I am fully stopped then it goes down to a normal idle speed. I am not sure if this is normal or not.

3, When switching the car off there is an engine judder like the engine is still possibly being fuelled?

4, Poor MPG, struggle to get 300 miles from a tank, this tank looks like I will only get 220 miles, however, it has been idling in garages this tank.

Someone please help me!!!!!