Looks like its buy two extra fans to exhaust the case out the top and see if that works. Otherwise its buy a new case and a better cooler which I'm guessing is going to set me back £200+ or drill a gazillion holes in the front panel so those 3 fans actually suck a decent amount of air in.
ETA
I've removed the paste that came with the cooler and used artic mx-4
@APW
I don't know where you got the information that the 212 is worse or even remotely similar to stock coolers but you're very much incorrect. I have issues with it for several reasons, it became the "go-to" popular response for budget coolers despite being beaten out by cheaper options for many years. It is not however even remotely close to the stock AMD coolers, it absolutely beasts them.
The prism is actually pretty decent, have one running on my 5800X and never goes above 81c although it can get a bit noisy. The stealth is poor though and definetly worth upgrading.Sorry I wasn't clear enough, I didn't say "stock coolers" in general.
The new ryzen come with the wraith prism, which specifically is fairly decent. The evo is a bit better but not enough to justify cost, few c at best. Might just as well spend £15 more and get something better.
The 212 is great upgrade for the smaller intel coolers or the tiny wraith stealth that comes with the low end cpus.
Update
I bought an Artic Liquid Freezer II 240mm and although an absolute nightmare to fit has dropped the temps from mid to high 70's to low to mid 40's when gaming . A drop of 35 - 40C