Bad service from staff at Pep Home Bluff

Not a happy shopper. Bought 4 blinds from Pep Home Bluff. They only had 3 black and 1 brown. I took all 4 and enquired if the brown was not suitable if I could return it and the teller confirmed as long as I keep the slip. The box was not completely intact. And nothing was said about it when i bought it except today when I want to return it and was told they can't because the box was damaged. I told her the teller said it wouldn't be a problem. The manageress took the box to the back to check it out which I feel she should have done in my presence. She then said the *****s were missing which is strange because the box was exactly like it was when I purchased it. I shop alot at pep home and today was not a good experience. I now have a blind that I can't use