I would definitley get in touch with your ISP then. It should NOT be doing that. There could be a problem with the wiring in your house or something. Or there may be some kind of interference.
That's what my mom has done, and yesterday, she called, and they said they were fixing a power outage in the area, and they told her what we needed to do (with the router and the computers) to fix it. Of course, we did that, and it didn't work.