Bad service

I have never experienced such a very bad and unprofessional service I received from Fabiani Menlyn mall. I took an item for exchange as it was a bit small. The guy who assisted us didn't explain the process to us as customers that he is going to credit the account and make a new transaction. On the new transaction we had to pay an additional amount of R360 I think of which if that was explained to us at the beginning we wouldn't proceed with the exchage. I found them very *********** and i was something to be done as they have financially inconvenienced us which let us to trouble. I need dis to be resolved ,I don't care how but it must be done.