Perhaps The Prince Should Sort Them Out.
News5 mins ago
No best answer has yet been selected by demo 7. Once a best answer has been selected, it will be shown here.
For more on marking an answer as the "Best Answer", please visit our FAQ.Sounds to me as if they are trying to rip you off.
If the car is running OK take it to another garage - a more reputable one - and get them to reset the ECU.
May have to be a main dealer or if you have a decent service manual you could do it yourself.
I'm not familiar with Fords but I've done a reset before on Vauxhalls and Volvos.
If the light comes back on, then you perhaps have a genuine fault.