Viviana, your domain registration and your hosting service are generally two different things. If you're not sure that you'll get to keep your domain (URL) when you cancel hosting with this current company then it's best to ask them first.
As to hosting - as you know
we offer hosting here at the forums specifically for VAs with business sites, but we do not offer a website building or template program at this time.
I'd suggest double checking the ownership of your domain (if you paid for it's registration then it's certainly yours) and then investigate some of the free website programs that are so popular among our members - I have heard good things about GoDaddy and Microsoft Office Live.
Good luck! I understand how frustrating a bad webhost situation can be!