Anyone advise what to do?
I have a hyundai ioniq with 90000 just under on clock.
It's got a 100000 warranty as it's a taxi.
I've had problems with engine management light coming on pretty much since I first had the car.
Bought it from wessex on Penarth Road.
Never caused the car to drive any differently or effect the performance in anyway, so I've just taken it down to them over last two years now and again to see if it could be fixed.
They've told me various excuses why it was on and have changed the EGR valve, O2 sensor, injectors, to name a few things.
Anyway, a few weeks ago I thought, as the car was soon coming up to the 100000 mile mark and I was off work anyway, then I should book it in again with wessex garages and get it fixed finally, they could have it for as long as they like this time as I'm not doing the school runs.
So, I booked it in for the Monday morning 2 weeks ago, and 3 days before which was on the Saturday I filled up the tank with petrol at sainsburys in pontllanfraith. Blackwood.
I only had about 30 miles left in the tank so filled it right up.
Left the garage in blackwood, then drove to Cardiff, done a few fares without any problems, then drove home to Cwmbran.
All was fine.
Monday morning, I drive to Cardiff about 6.am. Do a job before I drive it to wessex garages at 9am still running fine no problems with car whatsoever.
Drop car off, come home to Cwmbran, 2 hours later I get a call from wessex to say that my car is kicking out black smoke everywhere when they put it on the ramp.
They say they think it's contaminated fuel.
They can't do anything with it.
I ask if they have the right car as I've not had any problems with it?
They say yes it's my car and I'm dumbfounded by this.
I'm told it will be a cost of £249 plus vat to do a fuel contamination test and I'll be liable if it comes back positive, would I agree?
So i say yes.
They tell me that the engine could be knackered if Ive miss fueled it and thee warranty is now void.

I believe they've tampered with my car and done this themselves to get out of doing the warranty work.

Spoke to sainsburies, and a guy who is technical manager of UK fuel at sainsburys called me and has now taken a sample themselves.

Got result back from wessex to say that it's definitely been contaminated which I find bizzare as how would that car have been able to run as normal all that mileage that I done since Saturday without me noticing?

I'm now waiting on the sainsbury guy to get back to me about they're tests results.
He said that wessex results showed that my car had about 1-2 litres of diesel in my tank. My receipts from fuel all say that I've put the correct fuel in.
If this sainsburies guy comes back and says its not they're fuel I am ****ed.

Anyone know what I should do from here?
Where do I go next?