Where and what Dept in the Philippine Bureau of Internal Revenue can I report rampant corruption?

May I know what Dept in the Presidential Congress should I report these rampant corruption behavior? They asked my wife to pay P500,000.00 in Taxes and Revenue for her business there but she was given a Reciept of only P200,000.00 net paid ( Meaning that the rest P300,000.00 was diveded among themselves as thier expense money. And theres nothing we can do about it they said its the norm of their so called JOB....Public Swendlers I call them all. Please anybody help or I'll Email my President here in the U.S.A.