I am disgusted and dissapointed in Pick n pay !!!

I bought a box of dewfresh milk from picknpay senaoane and when we open the second one the milk was spoiled and smelly I then took the whole 5 cartons of milk to the shop for a refund/exchange, I met a manager mfuneko who said he would assist me he bought cartons of milk to me told me to open them and smell to check if they didn't go off I should take it then refused and asked for a exchange in a box not single cartons to my surprise the store had no stock even of other brands I took 2L of milk and I asked him how the refund would work as I am taking 2L and not a box that is when he started attacking me and telling me he is doing me a favor I then asked what favor are you talking about I paid for all these I need to know how I will be refunded he then said he is not going to help me anymore as he is losing money if he gives me a full refund he is cancelling everything I should go and get the other empty carton before he can refund me I then told him to deduct that full amount from my refund as I wont scratch in my bin and waste petrol for it he then insulted me in front of customers is this the way of treating customers? I called cs spoke to miles and Amanda no feedback to date