If your domain name is not currently working as you expect it to, you should contact your hosting company (the one who provides website hosting, email and other services) to enquire what may be the issue.
It is also possible that your domain name has expired and was not renewed in time. Domains need to be renewed every year in order to remain active. Please contact the company you last used for registration of your domain name. If the domain is listed as being with Tucows/OpenSRS then you need to contact your domain Provider to have the domain renewed. We also have a section on Renewal and Expiration of domain names on this website which may be helpful.