ATT combining land line service with internet

I have local land line service and internet with AT&T and no longer want the local land line.  I'm paying $49 per month for the land line which and can only call locally.  I want to keep my internet service but no longer want the land line and AT&T tells me they cannot separate the separate the phone service from the internet.  I find that questionable.  How can I get them to cancel just the land line?