I've been trying to contact them for literally wee...

I've been trying to contact them for literally weeks via phone or email. They don't seem to work or be there EVER. Your call goes straight to "full mailbox" or just unanswered at all, no matter what time or day you call ( yes I did call during hours that one is supposed to call and not during holidays). They don't respond to emails either. Very unprofessional and frustrating