I also need to interject here; the reason your files were all erased is because there was not a single one that wasn't infected with highly malicious code. I reviewed the dispute you had filed after being suspended due to a compromise; when I investigated the account, there were literally thousands of malicious shells and DDoS scripts uploaded to the account. Every single core Joomla file I checked (which was all of them) were also infected. In a situation like this, because we need to remove the malicious software prior to unsuspending the account, all files had to be erased as there were none that were uninfected.
You can still upgrade/reinstall by using the same database as you had been before (that is not a file and thus wasn't part of my malware review), however to do so you would need to upload fresh, vendor-supplied core files. Again, the database is intact (unless that was also compromised by the malware, which is possible but unlikely), but the files were so heavily compromised there was no choice but to erase them.