Extremely Poor Customer Service

I placed an order online over the weekend of the 26th August, there was a special for buy 3 and pay for 2 items, however on check out the 3rd item did not subtract, so I paid R799 via EFT, well I made contact immediately via online call centre and was advised that someone will call me on Monday to rectify and I will be refunded my R179.99(cheapest item free) , well Monday no one called, I called Tuesday was told once again someone from the accounts will make contact. Today I receive an email saying one of the items is out of stock (R269.99 duvet cover) and a voucher is attached to it. Why must I be refunded via voucher when I made EFT/cash payment? As well as why should I make payment for the 3rd free item? Today again I made a call was kept on hold for a while until I hung up, pathetic service from Mr. Price Home. Are you agents trained to always pit customers on hold and lie that they checking the order, SIES MAAN.