Fix customisation made on hotel booking plugin wordpress php

have a website with hotel booking system, it is using WP Hotel Booking plugin. I need it to be customised so that it has the option to book rooms which are normally for more than one person, as single occupancy booking. The changes need to add these: Room settings needs to provide a normal price (when booked with more than one person - usually 2 guests) A settings to set different price for 1 guest only booking. The prices then need to change accordingly on all pages where prices can be displayed ( mini cart, cart, extras page, checkout, email confirmation....) Prices need to add up to correct amounts if multiple bookings are made in a single order. Price for multiple days needs to display correctly, single occupancy and multi occupancy need to be capable of being booked at the same time (double room booked as 1 guest from 1st of January to 4th of January and Family room as 2 guests from 8th January to 14th January. We had someone do the changes for us, they managed to use custom fields to allow us to give different prices when a room is booked as single occupancy however the cart does not show or add up correct prices when multiple rooms are booked in a single booking.