Pick n Pay online clothing

I placed two orders online on monday, i received the one on wednesday, which is the wrong colour, i mailed them, no reply back, i phoned them thrice and when i get an answer the call drop, i called them again and finally got through to them, they said they gonna reply back to my email but im still waiting on their reply back, i received my other order today which is also the wrong colour, i called them again and the same thing happened, i went instore and they said they can refund me but they can’t refund my delivery money back but how am i liable to pay delivery for a mistake online made.