upload 0.00 / dl at 20% replaced modem, line quality checked

You guys sent out a replacement modem yesterday.

 It didn’t help. The line quality is obviously the problem since every device I have is having issues with upload speeds. Even download speeds are 20% of what they should be. Wired connection, wireless connection, cell phone connection. It doesn’t matter. Zero upload speeds. I have nothing between the wall and the router, and you guys installed the cable going to the router.

Please fix.