Thieving behaviour

I had to change my flight a few weekends ago and the change fee was more than the difference in ticket price. When i asked the call centre agent if the change fee was not a standard rate, i was told that it varies according to the ticket price. Such a joke as i don't believe the agent has to do anything more on a expensive ticket than on a cheap ticket. it takes less than 5minutes to make a change to a ticket if you have all the details ready. I also found out that if i change my ticket i have to pay the difference in price yet if the new ticket is cheaper than the one i first purchased, Kulula does not give you the difference back.