Failed to deliver want my delivery money back

I bought a Silicon ring on the 15th on takealot.com. They failed to deliver the ring and they credited money into my account .I then checked and noticed it was only the money for the ring only and the delivery money they did not add it sent them email asking them to refund my full amount as they were the ones that failed to deliver but not they just deposited the purchase amount back into my account .I was so dissapointed as none even called to Let me know that they would not deliver and when you call they don't pick up your calls.All I want is my delivery money period it's not my problem that you failed to do your job but taking my money for no good reason it does not work .I need my money back please .