Why isn't the Government held accountable for its Deceit?

Many Brits (particularly in England/Wales) are unhappy with immigration. If that were not so we would still be in the EU. But net immigration has gone up since Brexit! Both Leavers and erstwhile Remainers are victims of deceit by this Government. This is very serious. It shouldn't be ignored. Or swept under the carpet. The Government should be held to account.