How to turn off Netgear r6300 router wireless internet?

I have a Netgear r6300 router and I'm currently living with my roommate. We both have Xbox 360's except his is wired and mine is wireless. I'm tech savvy so feel free to get technical in the responses. Basically what is happening is he has made it so only his wired connection works and my wireless connection won't. I have tried connecting my laptop wirelessly as well and it won't connect, but the second I plug it into the r6300 with an ethernet cable it immediately begins working.

Just some further details: I have the router login and there aren't any settings I can see that would alter me not being able to connect. The SSID is still broadcasting, but it won't allow me to connect to it at all unless it's wired (it won't even let me connect wirelessly to configure to router). My roommate some how used his iPhone 4S to set it to this state while we were playing. We both have the router login. So I've decided to turn to Yahoo. Time to get a new roommate right?

Long story short: Can connect and access the internet with wired connection. Can't even connect to SSID on wireless connection right now.

Please help and feel free to ask questions in your responses if I'm not providing enough detail.

Added (1). @NERV Agent: The Wi-Fi password in the settings hasn't been changed so I'm sure we're using the correct one. Thanks.

@Hayden: I have tried this on multiple computers and a couple of xbox 360s so the wireless adapters aren't bad (plus, they connect to my phone on mobile hotspot). I know I can reset it, but I'd like to know how to solve this just in case it happens in the future.

Well, it seems like your MAC address for your devices are not blocked, so I've been thinking--did your roommate changed the wireless encryption password (AKA Wi-Fi password)?

Log into your router and do a factory reset. If you can't even do that, stick a pen into the reset button in the back. I know this is obvious, but make sure you have the right code. Only other explanation is that the adapter on your laptop is damaged. Try to connect to another network. (such as free Wi-Fi at mcdonalds)