Unfair customer treatment, ********* charging

Dial-a-bed Centurion conceded that they overcharged me on the sale of the beds and the mattress covers, promised to refund me, and then did not fulfil on their promise. The one staffer confirmed that they would beat any price out there, and the other one confirmed that they will refund me, together with the manager, but they have since gone quiet. Their invoice was received days after I paid, and it was not clear how much I was charged for the individual items. The prices on the invoice differ from what I saw at the shop. No clear explanation was given by the salesperson and the manager.

Dial-a-bed policy says free delivery for orders over R3000 and within 50km radius, which I qualified for, but instead they charged me for it, and manipulated the invoice so I have no idea how I was charged for the beds.