I agree in principle that if you book a room for more than 2 persons then all guests should be catered for in the room as stated in its description but. As in my previous post I stated that if you pay $100++ and $80++ for an extra adult then extra bedding should be included in that charge if/when requested as was the case at the Intercontinental and Crowne Plaza.
There is no detail of what the extra person charges are for as in my booking details it still only said breakfast for up to 2 adults so what is the extra person charge actually covering if not the required bedding, $100 worth of toilet paper maybe?
I am wondering why the OP wasn't charged these extra person charges as every IHG hotel I have booked added them when booking for 3 adults.
Anyways good luck when you contact the hotel and I hope things work out in your favour.