False Advertising

We are trying to mend a booking we made on your site and there is no option to do so , when we try and make the changes via your team you want to rip us off . We can see the site clearly requires an amount of 15k and when we call yourself you want us to pay 20k . What exactly causes the huge difference because merely having a human pressing a computer cannot amount to 5k extra . We would like to amend our booking as per the price on your site not what your consultants are pulling out of their thumbs