you must meet these 2 requirements.
1- If The account is using at least half (50%) of it's current disk space allotment.
2- if The account has a valid (i.e. working) website that follows the Terms of Service (TOS).
After you request the upgrade (if you qualify with the above 2 requirements)
wait for staff/ Anna to see your request.
support only checks the free forum periodically,
(so a reply may not be for a while)
an alternative to try to get a faster reply if needed is to
e-mail them.