HORRIBLE CUSTOMER SERVICE!!!!!!1

i purchased something online on Sunday the 29th of August with the option to pay in-store before shipping. a day later I received an email that I need to make a payment at any Mr price store which I did that afternoon and only to receive another email the following morning that my order is canceled. I was then told they will give me a voucher which I refused cause I paid in cash I don't see why I should be given a voucher, considering the type of service I am getting from you i wouldn't want to spend a single cent of mine with a store that does not give a damn about its clients. its been over 7 days and I still have not received my money back