ONT still not configured even after a week

my fiber was installed on the 20th of November the installer said it should only take 3 days but needless to say, I have still been waiting for the ONT to be configured I have called them and asked what is going on but all I ever get is that it has been assigned to someone.if I type in my isp username and password in the internet settings for my router I get a message that says cant access the remote server. So if anybody can help me out please do so cause I don't know what else to do. ref number 26990