Channels that have demonstrated more “risky behavior” will not receive access to Stories during the initial expansion, for example, channels with 2+ strikes. For us to help you better, could you send us a screenshot of the 'Status and feature' page? Keep us posted.
Stories feature is being rolled out gradually. You can file a feedback report with these steps: https://goo.gl/1ckkO5 . While every individual report may not get a direct response, we do review everything and use the details to investigate and fix issues.