Um... just checking, is it a Pro or an RT? There is no such thing as a "Windows Pro RT 8.0". That wouldn't even describe any kind of device!
Windows is an operating system family.
Windows RT is an operating system product line that runs on ARM tablets.
Windows RT 8.0 is the release of the Windows RT line that was present on the original Surface RT from Microsoft.
Windows 8[.0] is an operating system that runs on x86 and x64 CPUs powering desktop, laptops, tablets, and so on.
Windows 8.0 Pro is a specific edition of Windows 8.
There is no Pro edition of Windows RT.
Surface is a line of tablets from Microsoft.
Surface RT is an ARM tablet by Microsoft that comes with Windows RT 8.0 and is upgradable to Windows RT 8.1.
Surface Pro is an x64 tablet by Microsoft that comes with Windows 8 Pro and is upgradable to Windows 8.1 Pro.
There are a bunch of other things, but hopefully you can now speak more clearly about the problem...
Anyhow. So, you have a Surface. It's either RT or Pro. It's bootlooping. I feel compelled to point out at this time that XDA is *NOT* a product support forum! Unless what happened was the result of applying some hack you found on here, this is probably not the best place to look for help. There are actual support forums, not to mention real tech support options where you can talk to people who have the ability to do things like issue warranty replacements. That is where you should be. But, with that said...
First of all, unless consumer protection laws are *way* weaker in the Netherlands than the rest of Europe, you should be covered. One day would fall under lemon laws even in the US, I think.
Second, considering that you tried putting the ISO files on the flask drive you talk about using, I'm skeptical that you have "applied them both in a good way" as that is never, so far as I'm aware, the correct way to do it. For example, you may have neglected to make the drive bootable.
Third, have you tried connecting a keyboard (via USB) and using that to access the recovery options? Holding the volume buttons *should* work (although I forget exactly which ones you hold for which effect) but it's possibly work trying a keyboard as well/instead. The Touch or Type Cover keyboards would not work here; the EFI doesn't have drivers for them (only for USB, which they do not use).
Win8/Windows RT projects:
List of desktop apps for hacked RT devices
Native Access WebServer and Libraries
WP8 Interop Unlocks
Storage Cleanup tool
XapHandler, Root Webserver, OEM Marketplace XAPs, Bookmarklets collection (Find On Page), Interop-unlock hacks.
Do not private message me with questions that should have been posted on the forum!
Not only are you wasting your time - I'm not going to bother writing an answer to such a question for only one person - but I will probably block you from PMing me in the future as well.