Zara menlyn experience

I recently Bored a dress from Zara in Menlyn and lost my Receipt, I don’t know how I misplaced it,I went to Zara to exchange my dress since it still has a tag on it, then they said to me I cannot return the dress without the receipt,of which it’s not the first time I have done that and I just want to exchange the item since am pregnant and it’s too small, now am stressed out don’t know what to do with the dress,and the treatment I get from those ladies all the time I go to the shop is really unpleasant,I just want them to change my dress then I’ll stop shopping there and go we’re am treated like a customer