Please show me that you understand the problem and explain why you\'re the person to help fix it.
I understand that you need to remove the 'www' subdomain and make the naked domain the default wordpress domain so Google rankings are not affected. Yes, this can be done without moving website, just need to check HTACCESS and DNS to see the issue. Can you tell me if anything was changed by you?
Proposal:
Hi there, I have worked with Managed GoDaddy wordpress hosting and would love to first carefully check your site's DNS records to see why and what it changed and if it's in the HTACCESS or the DNS. And then I'll move it for you, hopefully without any down-time. Can talk to GoDaddy support too on your behalf, if required. :) but hopefully we wont need to.