Burnt out coils on a 330Ci

[Scania164]

I don't know if anyone can help, but my car the other morning started to mis-fire on start up and then the engine management light stayed on. I have an independent Bmw garage take the car away and so far they say 2 of the coils have melted ?? , they have replaced these but again they have burnt out ?.They say there could be a problem with the Ecu but i'm not so sure , Any idea's ????????