Thank-you for all the advice everyone, was nice to know that this was not simply a "common fault". Thought I would take the time to update everyone on this as it may well come along in another guise over the coming weeks and months...
After my last post I decided that rather than trying to unravel the whole deal I would see it through as I really like the new car in every respect apart from the EML issue. Mazda UK confirmed that an ECU software fix was DEFINATELY required and even sent me written confirmation that it was totally fine to continue to drive the car.
After 6 more weeks with no news, I got a little bored of waiting, and took the car to another Mazda dealer and paid £58 for them to run the diagnostics and give me a copy of the paperwork as I thought this might come in useful later on. The code returned was p0131 relating to the air flow sensor / oxygen sensor circuit being out of range with a low voltage input. The technician informed me that in this scenario they usually change the O2 sensor first and then re-check for further fault codes. They also let me know that there were no technical bulletins, or advisory notes to dealers concerning this, which would usually be the case if a software issue had cropped up and caused deviation from the "normal" sensor replacement procedure.
So I rang Mazda UK to inform them of all this, and they again opened a case, rang back after a few days and told me that after re-checking this DEFINATELY was a software fault and a fix would be developed in Japan by the end of June for certain cars that demonstrated this behaviour. They also said that they would not pay for the dealer to replace any other components until the "fix" was released.... Case closed again.
So I waited diligently until the end of June and low and behold I got a call to get my car back in as a "technical expert" was visiting all the way from Japan and was in the dealership for the day with my "software fix". The dealer came to pick up the car and I called later in the day to be told...
The chassis number of my car was not one of those affected by the software bug after all and so this would not make any difference. They then changed the Air flow Sensor as dictated in the repair procedure and this cured the problem. Apparently even though my car was not affected by this software bug, apparently one does exist and a new technical bulletin will be issued shortly as according to the dealer mine was the first car they thought was affected, and the first to be seen by the "technical expert".
now I am at least happy that after 3 months I finally have a car that works... having said that, I am also mighty ****** off at a few things:
1. There are only really 2 things that commonly go wrong on this circuit, O2 and MAF, so if it isnt one, then why not change the other in the first place ???
2. What is the point in having Mazda UK as an escalation of customer service if they simply believe the dealer over the customer and shut your case without any investigation at all ???
3. I am now out of pocket for the investigation fee at the other dealer, no loan vehicle was ever offered at any stage, and despite Mazda UK's assurance that the light would not cause further damage, surely having the fuelling out for this length of time will knacker my cat converters.
1. As others have indicated above, ALWAYS take a loan car from the dealer for the duration and make sure it is as much of a pain for them as it is for you.
2. Dont even bother ringing Mazda UK as they are a total waste of time and space.
3. Dont expect any offer of good will from either the dealer or Mazda UK even if you are waiting over 3 months for them to fix the issue.