Missing Store App fix?

Hi peeps,
I'm not very computer savvy so bare with me. I upgraded to windows 10 which went fine but my Store App was missing/corrupted - all other aspects of win 10 seem to be working absolutely fine. I contacted tech support who spent just short of 5 hours remotely acessing my pc to try to fix the issue. Their only solution was to advise me that I would need to purchase a very large external hardrive and a USB and completely reset my computer. They also advised that I would have to reinstall all the programmes which I have currently on my pc. Given that my 1T hard drive is 80% full including over 100 programmes this doesnt seem a viable option. I currently have very poor internet connection and am reliant on mobile wifi to make downloads. Time wise this can take over 6 hours to download a single programme. In terms of cost I have to pay £30/10G of downloaded data. Downloading Witcher 2 (which I have already bought and installed) which is excess of 20G would in itself cost me £60+ just in data useage and could take 2 days to download. Thats just one programme!

All I want to do is find a way of downloading the store app so I can puchase/download other apps from the Store. Any help much appreciated.

Cliff S said:

You can try these tutorial. the first one tries to repair the store, the second on is for a repair install, which keeps all data,universal apps and 3rd party programs.

Store - Re-register in Windows 10 - Windows 10 Forums

Repair Install Windows 10 with an In-place Upgrade

Thanks for the propmpt reply - unfortunately I'm pretty sure that the tech guys from MS tried this while they accessed my PC for 5 hours - they also tried inputtin all kinds of complex looking codes and command prompts all to no avail.
The second option looks a bit more promising though looking at some of the screen shots posted they also look similar to what the tech peeps tried. In addition I would be very nervous about attempting this as it looks way beyond my level of expertise The only part of windows 10 that seems to be missing is the Store App - all I want to do is find a link where I can download it as per other apps and programmes - this I would be capable of:)