Petition Tax Offices not sending employers the right code which means you have to pay back money

Whether you have one or more jobs the tax office sends companies your code, then they write to you that you owe them money as you have underpaid and its your fault because you should have checked, REALLY do i work for the TAX Office?????????????? no i dont, if this is the case then lets all make up our own codes as it seems to me that the government and the TAX OFFICE don't care, they don't want to take responsibility. They should do their jobs properly and stop blaming the hardworking individual for their mistakes. And they say working pays REALLY well i supose it does to them as when they get it wrong you have to pay anyway. SORT IT and stop blaming individuals for the TAX OFFICE incompetance.