SurveyMonkey's developer API stuff is provided by Mashery. If you take a look at the docs you will see a status code listing at the bottom of the page you will see what the various types of 403
errors.
Your code shows this: "X-Mashery-Error-Code": "ERR_403_DEVELOPER_INACTIVE"
and based on Mashery's docs i'd probably contact them directly and try to find out why the API key you are using to access the Mashery API is not approved.
My hunch is that the problem is probably not with SurveyMonkey directly.