MR PRICE ONLINE SYSTEM ROBBING CUSTOMERS AND POOR SERVICE

I have no idea what is happening with Mr Price's online payment system and their online shopping as a whole. So yesterday I was trying to purchase something online, when I got to the payment page, I paid but instead of sending me a confirmation email with an order number, system tells me I have no items in the cart. So I repeat the process.. it did the same thing. I later realised that the money for the item I was trying to pay got deducted from my account - TWICE. So now I am sitting here with my money gone, no confirmation email and no one willing to help me out with this, even after I called, emailed and even DM'd their twitter account. I am a loyal customer to their online shopping system but this is unacceptable. What must I do now???????????????????????????????????????