Get Execution status stuck in processing

[Will Savage]

I've been testing imports all day and its been working fine. But all of a sudden one of my imports is stuck in 'processing'. 

{

    "status": "PROCESSING"

}

Is there a way to cancel this? The docs say this:

"External applications can cancel an import execution they have started as long as they haven't signalled data completion."

Well data was signaled as compeleted. So what can we do?

thanks