Several times in the past year I have had to deal with new clients that came to us because they weren’t getting good service, or because their previous web design company didn’t know what they were doing. In several cases, we had to fight the previous web design company to get the site (and domain name) moved to a new server, get logins for web applications like Joomla and WordPress, and a bunch of other stuff.
Often, the web design company held the domain name and webhosting in their own account. One client in particular was only given partial access to their Joomla site, so I couldn’t back it up to migrate it, update plugins or add (and edit) users to give MYSELF full access. One company even changed the ftp login when they found out that they were losing the client!
There is an easy solution for this: control ALL of your own logins. It’s easy to let a company register your domain name or hosting, but you should take the time and do it yourself. NEVER let your web design company hold the registration to anything. If they need to access your hosting account (as they will), give them the login. But keep everything in your own name. That way, if your logins are ever changed, you can contact your hosting company and have them reset the login and send it to you.
Doing it yourself will take extra time, but it will be worth every second. Trust someone who has seen this happen multiple times, and has had to deal with it (and charge the client for our time).