not abiding to refund terms and conditions

I went into Mr Price clothing in Gateway to return 3 items and get a gift voucher to use at the Ballito branch as I could not find something suitable. Due to the current load shedding, I was unable to do so and went to Ballito today. As there was not enough time to choose anything, I notified the Manageress on duty that I have a return & she turned me away saying that she needed a receipt or gift receipt. As per their policy at the back of the sale slips it states \If items are returned without a sales receipt within 30 days we will exchange no problem and if you can't find anything suitable we will issue a gift voucher for the current purchase price". Even stated that to her but she was so rude and ********. If Gateway branch was willing to complete this return/exchange (which she was notified about) why couldn't she do the same!!?? Why should I travel back to Umhlanga (which is further away from home) to process a return when Ballito is closer and has the items that I needed! Where is the customer service!!?? I've been in Management in the retail field and have never treated my customers this way!"""