Did not get our refund as promises in a letter

We booked in @ Riverton resorts Kimberley on the 05.01.2015. We booked for two nights,just to fine out the fridge and the stove is not working and the place was very dirty.<br> They replaced the stove and the fridge after 2 hours of making a lot of calls to them and left the broken appliance's in the chalet. We agreed with James the resort manager that we will only stay the night and they will refund us for the other night. He gave us a letter to confirm everything and said they would refund us within 4 working days we are still waiting for our money