Dis-Chem Refuses Refund

I placed an order online a few months ago and Dis-Chem were unable to ship a full order due to stock constraints. Now that is completely understandable, but just refund me the money for the items that were not supp****. Am I incorrect in assuming that this is too much to ask?

I have spoken to so many agents telephonically and on email, and they are convinced that there was a partial refund to the money that they still owe me, but nothing has reflected into my bank account and they are unable to provide me with proof of this. This week the Woodlands branch decided to just hang up on me. So here we are...