Review Homechoice is unethical

I do not understand about homechoice ethics:The amount that I had to pay for two items I had ordered was paid and I sent the Proof of payment.I am not sure where home-choice comes up with an additional amount of R1214.94?
I requested them to cancel any order that may have been made to that amount and only send me what I had paid for. I had submitted the invoice for the original amount I had to pay which was R1653.04. This was paid and only one item was sent to me out of the two items required to be sent to me. Had this amount not been paid, Home choice would never had sent me the one item in the first place. Even if you deduct the amount from the two items I had ordered, it would still not come to R1214.94. Homechoice had cancelled my order insisting that I pay them the amount they are demanding before sending me what I had ordered. I had sent them all the proofs and even suggested that the error maybe on their side but to no avail. I had on a previous occasion ordered another item and I was sent an email stating that they are out of stock. I was never able to get my money back from them. As this was for a small amount I did not think anything of it.