Change mapped domain

Greetings,

I have a blog (zappingmental.wordpress.com) which I’ve mapped it (zappingmental.com). And I want to change both addresses to primitivismos.wordpress.com and primitivismos.com without loosing my followers and stats.

How should I do this?

Researching on the forums I notice that there is only information on how to change the dot wordpress address. Is it because the mapped address changes automatically once you change the former? Regarding the followers, I understand the staff can do it in a jiffy; however, support contact is not available, it redirects to FAQ’s. Would buying the “redirect site” help me keep my followers?

Thank you