LG G3 Internet problems

I have recently been experiencing problems with my android G3. I currently work in a lab as an intern and have been experiencing problems with the WiFi and its connections. I can connect to the wifi fine with my computer but when it comes to my phone, I can't connect at all. It used to ask for a username and password along with accepting the terms and conditions because it is one of those free wifi's but it hasn't been asking it. Also, I cannot open my google play app as well. The phone says it is connected (without the exclamation mark appearing next to the signal) but when I open the page it says it cannot load. So far I have tried the whole airplane mode and restarting the phone. I have also tried to remove my google accounts from the settings page and even that doesn't work (I press remove and it doesn't respond to actually removing the account). I can't really restart the routers here because they are centrally located and inside a tech room.
Any suggestions?