If you accepted the offer without stating your concerns at the time it is unlikely that the council will allow you to move again (unless you gain further points).
With 2 boys there is no issue at all about overcrowding. The way to calculate whether you are overcrowded or not is complex and does not only take into account the square footage available - the ages of your sons, other adults, whether or not you have space to sit and eat in your kitchen etc. are all taken into account.
Of course you have a right to complain and may wish to speak to your local ward councillor to see if they can offer any advice and assistance with a further move or to help with any complaint you may have.
Good luck, whatever you choose to do.