CHARGED TOO MUCH AND I DONT HAVE PROTECTION

ON 2/21/14 I WAS BILLED $59.99 NOT SURE WHAT THAT PAID FOR.  THEN ON 3/6/14 I WAS CHARGED $179.99.  I TRIED TO GET THIS CORRECTED BUT GOT NO WHERE.  NOW MY COMPUTER IS SLOWER THAN SLOW AND HAS POP-UPS GALORE.
JUST WHAT HAVE I OVER PAID FOR!!