Extremely high Forex rates with FNB

I have been a customer with Fnb for over 13 years now. I always figured when I purchased things online overseas that it was just part of the fees. Ever since I opened a second bank account I realized that its not fees its just *******. Fnb literally charges 50c more than the current exchange rate of the dollar. It is not the first time I've seen this. I have purchase probably over 20 times and not once did I get anything lower than 40c more than the going rate. I can understand that a bank needs to make money wherever they can but how is charging 50c more than going rate even legal? I funded an overs**** account last night and I even calculate it at a higher rate knowing that Fnb would quote way higher, to my surprise I even under estimated. The time I made the purchase the rate was about 13.77. They charged 14.26. Whenever I fund offs**** investments or buy something overseas with my Nedbank account I get charged probably like 5c more than the going rate, in fact there were times I got a favorable rate where i got better than current. How is this even legal? Needless to say I will be closing my FNB accounts soon and sticking with Nedbank