KFC sates they make a loss if no ice used

Have been to KFC numerous time always have the same problem if I don't have ice with coke or any drink they literally fill the glass of coke halfway.and when u complain you get them screaming and telling you that's policy?! What kind of policy that u get a HALF glass of coke?? So fed up it's been happening all the time at different branches as we'll. and besides the attitude the staff gave today was pathetic.