Bad service from a manager

I went to the branch in voortrekker belville for my free coffee on my app but i also bought a boerie and egg burger but then the coffee dissappeared off my app and it didnt go through on their sytem.i i formed the staff member and then she called the supervisor the supervisor came i again explained dhe then we t ro the Manager which was soò rude said he doesnt do this i cant just ring up a free tea and exchange it for coffee and this never happens as if i was lying . Hes so unkind to me and if this is how you treat you customers wow.