K sku's are overclockable the normal 14700 or any non K's are not overclockable ..
Is your PC pre built or did you build it yourself ?
By default the cpu's cant come new in box overclocked !!!
even the KS cpu's are just better binned not overclocked
I doubt its been overclocked in a pre built system .
Even if the people that built it have OC'd it they should have stuck a bigger cooler on it !!!
I think the Be quiet rep is covering his arse on the wrong cooler for the cpu by telling you its over clocked !!
Best solution in my opinion is use some quality thermal paste make sure you mount ( i recommend a 360mm aio ) correctly and you shouldnt have issues in gaming if you go and cinebench allcore R23 its going to get toasty ..
My 14600kf struggles with the Noctua NH-U12A to keep it below 88c in allcore R23 where as my 7800x3d same cooler 80c same test ..
That said ive found the 14600kf idles cooler than the 7800x3d but much hotter under load !!