I have Comcast now, which works fine for me (I did buy my own modem and router, though), but I used to have DSL. When I first got DSL, Verizon supplied the modem. Well, let me tell you that modem was junk. I had so many problems with it, it was constantly dropping, sometimes it wouldn't work for days. I finally decided to buy my own (combo modem/wireless router) and all of a sudden, no more internet drops. No more problems. I think the ISP's supplied hardware seem to be bottom of the barrel in quality.
You could try to buy your own modem (they are not that expensive). I personally bought a Zoom - model 5431, and it works great for me. I have it hooked up to my own Netgear 600 (mfr#) WNDR-3700-100NAS. Set up was a breeze, the Netgear set up with the wizard was also a breeze. I am very lucky with my Comcast cable. I have never had a problem yet (crossing my fingers and hoping I'm not jinxing myself LOL)