Charge them through heavy infantry units, light infantry, like skirmishers, are a chariots worst nightmare. Also, don't stay in combat, charge through the enemy unit, and then send in infantry to exploit the gaps, eventually the chariots will have javelins too so once you're through you can pepper the enemy rear with javs while your infantry attack from front. Also, you chariots raise the morale of units around them, so just having them nearby helps keep your men from breaking.