Chef delivery: delivery moved on to build stage even if pull request is not merged in bitbucket

Our delivery project are configed to use bitbucket as repo. On Verify stage, click on approve button in delivery suppose to merge pull request in stash;

but if somehow the pull request get declined in stash due to stash issue, delivery server does not check the status of pull request and continue to build stage etc;

I would like to have delivery check status of the pull request and continue only if the merge is successful in stash. Thanks.