Lay-by Clothes not found

I placed a Lay-by at Mr Price, The Reef Centre, in Germiston. Yesterday when I went to pay it off, I was told that my parcel could not be found. I waited and waited thinking maybe by luck they will find it but no luck. I was offered a refund as a result of unavailability of my Lay-byed clothes. This may be due to negligence or human error, at the same it is also an inconvenience to me. Can you please intervene as I feel that Mr Price has violated the Laybye contract agreement as stated in the invoice-: "Mr Price agrees hereby agrees to sell to Phamela Motloung on a Lay-by system"