265 ECU and other dramas

Hey all, any of you fine folk in the Northern Hemisphere able to point me in the direction of a new "blank" ECU for my 2015 RS265? Anyone local to a Renault dealer over there?

Here's the TL;DR version:
Replaced the cambelt etc back in July (a specialist shop, not myself), then after putting it all back together the car simply would not start. The OBD scanner even drew a blank. It then went to an auto sparky who said it was the UPC, so I got one from Renault in Australia and that did exactly nothing. I was not impressed.
So they sent the ECU to a repairer who did God-knows-what, then it ran momentarily, then ran rough, then died again at which point they said it was the crank angle sensor. Replaced that, still nothing. Even less impressed.
After a month and a half at the auto electrician it went back to my mechanic in the same no-go condition it left in. The ECU was sent to another repairer who my mechanic uses, but he can't really do much as someone else has already screwed around with it. He suspects a hardware failure and is very reluctant to transfer mine to another unit as it'll probably just transfer the issue my ECU has, thus creating two useless ECUs.
No ECUs in stock in NZ or Australia, I do have a Renault agent waiting for a reply from the UK, and Australia have a 12 week wait!!

Cheers
Craig