Updated the suspension reason; couldn't find a phishing page, but an unprotected file uploading system isn't a good idea either since it allows -anyone- to use your account for file storage.
I did also forward this to one of our higher ups so they can take a look at why that particular file uploader triggered a phishing suspension when it shouldn't have; first time I've actually seen it do a false-positive honestly...
The problem is not that you have it, the problem is that you didn't secure it, as it is now anyone could actually use that filemanager and upload anything they wanted to your account, and that is a security problem
FTP is feasible with any internet connection, besides ones within businesses and education, in which case there are probably other things that you should be doing besides trying to upload a site. FTP will be faster in general anyway.
What sort of network are you on then? If it's your home network then your firewall way be catching the outgoing connections and all you need to do is allow access for these connections.
Anyway, you are still suspended because by having this unsecured file access you broke the terms of service by essentially having a file hosting service.