Any advice please?

[Maa]

Car suddenly started loosing power on the motorway on 25th June (1.2 petrol 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 said they would only take it to their nearest "Approved" garage. They suggested I drive it and they followed me to their "Approved" garage where it was left and they 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 and therefore 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 then told 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 was then told that the new (refurb) one was faulty so they ordered another one, 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 another.
Last week they put another (3rd) one in, and was told that one one had gone as well.
As of yesterday, 31st July, still not heard anything. They have now had it for five weeks.
Been on to the RAC this morning who are going to look into it as I pointed out it is their "Approved" garage, not where I had asked it to be recovered to. Waiting to hear back from them.
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'm not by any means a mechanic, so any advice would be useful.

[Trevor]

I think I would get onto the RAC and insist they oversee this situation.
I cannot see how an ECU has anything to do with a lack of compression and should be a straightforward job 
Keep us updated on how it goes

 

[Maa]

Thanks for the reply. RAC have tried to distance themselves completely from it saying basically it is my responsibility. Their latest is I need to get in touch with the garage and allow 8 weeks for them to reply. I have pointed out to them that the car was not recovered to garage of my choice but their so called "Approved" garage. Still waiting for a reply. Called the garage again this morning, they said they would call back this afternoon. No surprise that they haven't. They have now had it for six weeks.

[Trevor]

Threaten an ombudsman to the RAC directly and see what they come up with
They may have an independent assessor go to the garage which they should do if the garage is an approved repairer