If this is really the case then you have to find appropriate DNS Hosting provider, which will allow you to host your domain with them - providing Name Servers, where you will be able to manage/change A/CNAME/TXT etc. records.
One such provider is GoDaddy. Another probably is EasyDNS. Don't ask for more or for pros and cons and which one to use, because this will go out of the scope of StackOverflow.