4G LTE data is overriding my WiFi

I have a Samsung Galaxy Note i717 (the first Note).

Just recently I noticed that my 4G LTE icon on the top of my phone's screen is showing up along with my wifi icon, and therefore my phone is running on the mobile data rather than wifi, which caused me to go over the stupid data limit and I was charged for a new data cycle.

Anyways, according to my phone, I AM connected to my wifi, (or any open wifi depending on where I am), yet my phone still is using the data.  The only way for me to use the wifi is to go into Settings > Data Usage > Mobile Data where I have to uncheck the Mobile Data box.  Then, I have to restart my phone in order for the wifi to pick up, even though the wifi icon is showing on the top of my screen. 

Then when I go somewhere where there is no wifi and I need the internet, I have to physically go back into the Settings and enable the mobile data connection.  Then when I get home (or wherever there is an open wifi) I have to remember to disable the Mobile Data, then restart my phone to use the wifi. 

THIS IS VERY ANNOYING, NOT TO MENTION INCONVENIENT.  This just suddenly started happening on its own a couple weeks ago. 

Any ideas on what could be causing this?