I believe you're probably looking at the right field name, "name." Is it possible that the customer has actually named their campaign to be a number instead of what most of our customers do? We also have a campaign field called id that should be just a number. See this page for the campaign field names.
I'd be happy to take a look at the particular campaign if you want to email the campaign id or name and the Constant Contact username to email@example.com.