Flight Centre mistake and they unable to correct

My husband and I booked our honeymoon trip with Flight Centre in Claremont, 3nights Bangkok and 7nights ****et. Upon booking, the consultant Waleed had telephonically confirmed 7nights at ****et with latest flight out of ****et. Instead when I arrived at the hotel, my booking is for 6nights and I leave hotel on the 6th night which then takes it into 7th night at 12:10am. It was taken up with Flight Centre Teamleader(Angella) who has said she can only offer me a 50%discount on changing flights. Why should the customer be liable to pay double for flights when they confirmed making the mistake of booking 6nights and not 7nights. The next day I went to hotel manager and he confirmed we are suppose to be staying 7nights bec that is what was paid for. I informed the manager at flight centre, she however has not returned my emails and what seems like shes avoiding me. A total bad honeymoon experience. I do not recommend this branch to anyone, they apply pressure to make the payment with such a short timeframe then customers cannot review it properly. So unprofessional. All I asked was for them to change flights to accomodate our 7th night and they wont do it. Its an international company known all over and they cant even fix up their mistake.