Is there a legitimate way to stop a request "In Progress"?

Example, if your requested VM has a scenario that prevents the provisioning from completing such as a misprovisioned IP address, the request stays in "in progress" status for hours and hours. 

Is there a legitimate way to cancel the request in progress?

Does anyone know the default timeout value for an "in progress" request to finally fail?

Is there a legitimate way to cancel the request in the scenario that I've already deleted/removed the misprovisioned VM from vCenter?  A reboot of vCAC does not seem to do the trick here.

Thanks,

James