Why refuse with prescription letters

I have been taken from pillar to post by DMC, one would think they don't want to give consumers their rightful prescription letters. I called Woolworths and Foschini and was told that DMC were sold the prescribed accounts. When I call DMC I am told they do not have the accounts on their system and they don't say what happened to them as Woolworths and Foschini say they sold to DMC. All I ask is the prescription letters for Woolworths account number *** and Foschini account number ***. I don't understand reason DMC does not want to give prescription letters. Or one should escalate to NCR maybe so this matter can be SORTED? We cannot be made to run around like this. My number is ***.