Hole in undertray

Agree Tim, but still hits you in the guts.
Sorry to say this kinda story is going to be repeated time and time again as the number of Chinese imports increase, and the quality of construction and materials used are paired back to the minimum. The same story we had back in the 60'-70' with Japanese imported motorcycles.
Hoping things change.

Wow, will be interested to see the pictures of this damage. Bad as it is in this case, it sounds like a freak accident scenario where the wheelie bin wheel must have struck in exactly the right location to damage the port(s) on the battery.

Skilled cleaning and drying of the afflicted area and application of a quality polyurethane sealant would probably see the issue resolved for the life of the car for all of around £50 in materials and labour, but obviously that's not the world we live in!

PS, Will be interesting to see if the car ends up at Copart, and if it's sold as repairable salvage. If it does, it really will be back on the road after a tube of tiger seal and a new under shield!

PPS, That reminds me of a lovely Mk5 Golf I bought many years ago from Copart with "underbody damage" An alloy mounting tag on the gearbox end had a chunk missing from hitting something in the road, no cracks, no effect on the mount, it was truly trivial, but resulted in the quote for a gearbox change making the car a Cat C write off! I spent about 10 minutes tidying up the ragged edge with an angle grinder and Dremel until no one who didn't know how much the tag originally protruded would ever know anything had happened and went and got an MOT done. My brother used that car for the next 6 years, it was flawless!

DBedford: well you know what the "quality and construction" of the imported Japanese motorcycles did to the UK motorcycle industry - virtually gone on 10 years. Unfortunately that was largely down to poor design and build of the UK product. A 175 cc Japanese bike performed better than a 350cc UK model and oil leaks everywhere!
Fortunately (and largely down to the Japanese) the UK car industry is much better now.
But no room for complacency.

Its most likely gone down this route because no one wants to take responsibility for a repair and sign it off. Ridiculous situation. Don't be fobbed off with anything other than a brand new car. Many years ago a friend got a brand new Austin Maxi , two weeks in, the main clutch bearing let go along with the flywheel , basically destroying the gear box and engine . The dealers response was to find a four year old reconditioned unit with about 40000 miles on it and fit that . On return and opening the bonnet instead of a nice clean engine there was a tatty filthy lump which looked older than stated. To be fair , it ran alright but always left a bitter taste and of course devalued the car.

Thank you for sharing this story and sorry for all the stress and hassle you've been through. It really shows what's wrong with the current system. Surely there needs to be more pragmatic thinking by insurers, dealers and manufacturers? They need to bring in more data and expertise to make genuine assessments about the risks involved in these situations. Writing off a car due to damage to a plastic cover (caused by a piece of plastic)? It really beggars belief. A few months ago, I actually drove over a small piece of curb in front of a parking space because I forgot it was there when I drove off. Only now do I realise how lucky I was. I took it to the dealer the next day and they gave it a visual inspection for free and gave it the all clear.

I haven't forgotten - will post pictures soon. The last couple of weeks were quite the roller coaster. Insurance promised a 'new vehicle replacement' only to later came back to us to say all MG5 are out of stock and that it has now been discontinued (which we knew). We then rang countless dealerships and eventually found one which still had a pre-reg in stock. Most carwow and Autotrader adverts (even if new) are/were no longer available.

And, because I can't be cautious enough, I now also went for 4 year GAP insurance. The stress of not knowing if the settlement will be enough is not something I'd like to experience again...

I definitely learned a lot about the insurance mafia industry and will write it all up for others to learn from it once the dust has settled. Thanks for all your support - it helped a lot just having a place to vent and feel a bit heard.

@migros8 - so sorry to read about your incident, and I hope you now have another brand new MG5 on your driveway.
I can only imagine how your heart must have sunk when you were told about the possible damage to the HV battery.
Hopefully you can now put it all behind you, and enjoy your car once again.