Refund for cancelled lay-buy

I had a lay-buy for a daybed order 430792 from Rochester. The price of the daybed was R15 490.00 including delivery. I paid R6000.00 towards it. The order was a standard order and was not modified in any way to suite me. It was not a \Special Order Goods\" according to theirs terms. I've had to unfortunately cancel the order and was expecting to pay some kind of cancellation fee. I was told they would charge 30% cancellation fee. I asked what are the basis of this 30% and was referred to the back of my invoice for terms and conditions. Well, I checked the invoice and there are no terms and conditions. Also there was no lay-buy agreement or any agreement signed when I did the lay-buy on the 13th December 2015. This morning I got a payment from them of R1353.00 as refund from the R6000.00 paid. That is not even a deduction of 30%. I will be submitting a complaint through to the ombudsman as well with regards to this query. I need to understand how did they get to 30% when the credit ombudsman says 10% cancellation fee on lay-buys. Also can I be refunded the correct amount please! "