Reviewing our logs, I didn't see an outage on Sept 14th that would have resulted in not being able to process payments. For immediate issues that are impacting your stores' ability to make sales, it would be best to contact Shopify Support as they can get these types of issues investigated ASAP. You can do this by logging into your store through the help center, searching your question/issue, then selecting "continue" at the bottom of the page that displays the search results.
Trevor | Community Moderator @ Shopify - Was my reply helpful? Click Like to let me know! - Was your question answered? Mark it as an Accepted Solution - To learn more visit the Shopify Help Center or the Shopify Blog