I was under the impression that some of the MOOCs offered their content for free, if you were not seeking a credential/degree for the course.
A third party states the following:
"You must be logged into Coursera to see the pricing information. Courses may be available either on a subscription basis or for individual purchase. Many Specializations run on a subscription basis costing between US$39-79 per month."
Have you created an ID and logged into Coursera?
It looks like that may be your first step. Perhaps they don't have a large customer support department given that their model is online (and perhaps self-service).