Q: iPhone 6 4G not working

I purchased an iPhone 6 in December 2015. Everything worked perfectly up until recently when my 3G/4G has stopped working. I have plenty of data left for the month however no social media/webpage will load without an internet connection. I have had a sim swap, and restored my phone via iTunes but nothing made it better. Does anyone have any other ideas or will I have to send off my phone for repairs?