BAD INTERNET CONNECTION

I AM A STUDENT DOING MY STUDIES AND NEED THE INTERNET TO SUBMIT MY TESTS IN A CERTAIN TIME INDICATED AND AS YET TODAY I AM NOT ABLE TO COMPLETE THE TEST AS THE INTERNET KEEP ON SHUTTING DOWN. I DO HAVE UNCAPPED, BUT APPARENTLY THEY THROTTLE YOUR INTERNET IF USING TOO MUCH DATA, NOW I WOULD LIKE TO KNOW WHAT IS THE USE OF HAVING AND PAYING FOR UNCAPPED AND YOU CANNOT USE IT.