Accidentally mapped the zohodesk domain to a wrong address and a couple of other questions

Accidentally mapped the zohodesk domain to a wrong address and a couple of other questions

I accidentally mapped the zohodesk to a wrong subdomain on my website and now I can't access the zohodesk dashboard to change it back. 

Trying to access  https://desk.zoho.com/support/rolomit/ShowHomePage.do#setup/organization/domainmapping redirects me to the wrong subdomain that I set up and I can't access the dashboard because it returns a DNS error.

Additionally, can I get instructions for how to set up the domain remapping so that I dont make a mistake again?

Do I create a subdomain and then go change the CNAME records for that to customer-support.zoho?


Also, how exactly does live chat work for apps? Ex: I want my android and iOS apps to have live chat capability. Does that exist?

Do E-mail channels have to be whatever@<name>.zohodesk.com or can that be changed as well?