Minuscule Download speed, Normal Upload Speed with Cisco Linksys E3200 Router.. HELP!

I've had ridiculous problems with my router over the last two days, here's the gist of the problem:

Until yesterday, our internet speed had been perfect. 5 computers, and two xboxes worked just fine on our service plan of 50/mbps, fiber optic service.

Essentially, we have an ethernet jack in the wall that connects to our router, thus providing our network.

Yesterday, our service died. We were "able" to connect to the internet, but speeds had diminished to 0.02/mbps, essentially destroying all hope of getting on the internet. We tried calling our service provider, they were unable to help over the phone (reset the whole network twice, problem persisted), despite bypassing the router entirely and connecting directly to the wall-jack (the provider was able to register a connection, but no significant download activity). So, they sent out a worker to help us.

The tech was able to provide us normal service out of the wall (normal 50mbps up and down), with intermittent success, but still no success through the router either wirelessly or via LAN. Graphically:

Wall >>> Computer
Wall >>> Router >>> Computer (upload speed is still 50mbps, download remains 0.05mbps)

I have reset to factory defaults, installed the latest firmware, power cycled plenty of times, all with no success.

Any suggestions? I tried calling cisco, but they require I pay a fee for technical service, which i cannot pay. My product is under warranty, but I'd rather not send it in.

TL;DR Router problems on the download side of the connection; tried everything; please help.

 

Welcome to the forum, If the router is still under warranty, I would request a cross shipment of a new router or borrow a router and test with it.

 

Isn't plugging into the wall jack better?