Fed up

I bought a Samsung Tab 3 10.1 in December 2013 so I could use it for school. Now because my cell phone broke, I started using my tablet full time. When i try make phone calls, my network gets cut off or the person on the other side of the phone call cannot hear me at all. I have sought help online from technicians and many people get told that theres nothing they can do to try fix this problem. One of the suggestions was that i set my tablet on factory settings. Now what if I do that and it still doesn't work? Currently I'm on my second battery, 3rd charger and 2nd charging port. HELP ME!