Complant

I had a coat which I needed to exchange, I Google Bara contacts as I wasn't aware we have one in protea Gardens. I asked if it's possible for me to do an exchange without an invoice and the lady I spoke to agreed... Few days later I sent my brother to go do exchange and told him what to exchange with but unfortunately when he got there they did not have the item I wanted so the lady who works there even sent the picture to the group but no one rep****, so the lady personally spoke to me over the phone to say I can go to any Dunns to do an exchange as they can't rufund cos I dont have the slip which I fully undstood. This Saturday I went to Protea Gardens and to my suprise I was told it's not possible for me to exchange as I don't have the order number from the slip, I left the store disappointed which I felt either Bara or gardens are playing with me... Is Dunns system not the same if Bara they were willing to assist yet Protea Gardens sent me back??