Help needed with car breakdown

Just4me2

Car suddenly started loosing power on the motorway on 25th June (1.2 petrol Juke on 17 plate). Initially it cut out completely, but when the recovery service got to me, it started back up again.
RAC said it was not firing on one of the cylinders.
I asked for it to be recovered to my local garage, but they said because it was "driveable", they would only take it to their nearest "Approved" garage. They suggested I drive it there and they followed me to their "Approved" garage where it was left and the RAC arranged a taxi for me back home.
After a week, was told by the garage the timing chain had stretched, resulting in the valves being damaged on one of the cylinders resulting in no compression.
Was told the valves had to be ordered as a complete set total cost with fitting and new chain was £2k, not great news but said OK do it.
Next week was the garage said they had been sent the wrong size bolts for the head and waited another week for the right ones to turn up.
I was then told that the ECU had been burnt out as a result of the alternator spiking.
They replaced the ECU and alternator and was then told that the new ECU was faulty so they ordered another one, causing another week delay.
Then the replacement turned up and was told that as soon as they tried to start it, that too had tripped out, so they ordered yet another ECU.
More time went past, they fitted another ECU and was told that one one had gone as well.
I have contacted the RAC told them of the ongoing saga pointing out that this is their so called "Approved" garage, not where I had initially asked for the vehicle to be recovered to.
Basically they are not interested and have tried to distance themselves as far as possible from it.
One thing I have thought with regards to the ECU, could this have been damaged by the garage?
My thinking is that if the car had been delivered to them on a tow truck, then possibly it could have been damaged before. However given the fact that the car was driven into them or be it with no compression on the one cylinder, the ECU presumably was OK or it would not have started in the 1st place.
On face value. it would appear that the ECU issue has only happened since they took it apart not before. It also seems a bit odd that including the original, 4 of them have been burnt out when they tried to start it back up. I hasten to add I'm not by any means a mechanic.
With regards to the garage, all I get from them is "We will call you back". Needless to say, they never do. 
This is now approaching 7 weeks this has been going on for
Any advise would be appreciated.