In 99% of cases your ISP has nothing to do with needing to reboot your modem x times a day, as has been stated a lot of modems will crack under the loads torrents put on them, drop out due to bad line conditions or incorrect filtering, or are just plain shit. Either way call your ISP and complain, I know for sure Adam can check your line statistics from their end and help troubleshoot where the problem may be (if you're on an Adam dslam).
This is my home connection, completely shit conditions, a wag54gv3 on an Adam dslam. Most people would have a better connection than this, I only drop out every 2-3 days and never need to reboot the modem, neither should anyone else.
Downstream Rate: 3680 K
Upstream Rate: 864 K
Downstream Margin: 6
Upstream Margin: 6
Downstream Line Attenuation: 56
Upstream Line Attenuation: 31