Not changing gears on it's own

I have an automatic 2014 Civic. And when I
accelerate to get on the highway the RPM red lines
it doesn't switch gears on it's own. I have to let off
the acceleration then reapply. Even when I'm
driving 30 mph and accelerating I have to
constantly take my foot off the acceleration just
for the gears to change if not I red line and it
doesn't stop red lining. Please help.