All the SEC can do to a Form 15 filer (non-registrant issuer) is, under specified circumstances (if the stock price appears to be manipulated or if it believes that public information about the issuer is false or misleading), suspend trading for 10 days.
After that time, the stock can trade as a gray market stock as long as it gets a broker-dealer to file a Form 211 (per Rule 15c2-11) in order to quote the issue for continued trading. In that case, as a grey market issue.
So while the SEC can impose at most a 10 day hiatus in trading, only FINRA can delete a ticker and impose a permanent trading halt. Which FINRA can do even if a broker-dealer has filed a Form 211 and it meets requirements of Rule 15c2-11.