Your account has to be reviewed by an administrator instead of just the normal join team members due to being flagged as a potential multi-account. This can happen for a variety of normal reasons, such as sharing an internet connection at school/home/work, etc.
You'll actually need your old account activated again since you cannot have more than one account. Post a support ticket at support.swcombine.com and an asim will be able to help you out. The information about your old account can be retrieved from your IP address or from the match for the handle you tried to apply with, so if your handle is still pending, include in the ticket which one it is.