To Pep store at Doobsville

I'm angry an disappointed nje I went to pep home store in Doobsville to exchange the blinds I bought in Maponya Mall because I've already change it the lady refuse to change it again an said I've already made an exchange the lady was so rude nje an all I got the slip but the didn't help me cz they refuse so what should I do with this blinds nw cz I even said to the lady I also got the card I purchase with u can check the lady said I should go back to Maponya to do an exchange cz I've already done an exchange with this good it not open it still sealed with the price tag an ma slip