Well after paying all dues and development charges now the society is asking for additional development charges what advice. The society is in punjab
What society is it? where in Punjab? the society generally has this is the terms and conditions when we book the plots, so I don't think you will have much choice but to pay unless you want to forfeit your investment and potentially make no profit. The most re-known is bahria town for extortionate extra development charges, but if the society requests it, then I suppose you have to pay unless you can find a quick buyer whom you can sell to for a profit and explain to them that they must pay the extra development charges.