This bank just does not bother!!!

I drew out R1000 from their ATM one evening only to find out that when I got home that the machine gave me R100 short. The receipt confirmed what I asked for so I called them on the following day and was told that they will credit me within 24 hrs. I was also told that if this doesn't happen I must visit a branch and they will credit me. Needless to say it did not automatically happen so I went to the Westville mall branch who advised that they have logged it and will get back to me. It's more than THREE WEEKS later and still nothing. I get it that R100 probably means nothing to them BUT THAT IS MY MONEY WHICH I AM BEING ****** OFF. I received a ref *** saying its in progress on 15 May. Nothing since then! I will proceed to the OBS for banking services as I will not chase after them and invest any more inconvenience only because they are so ***********! Surely they balance their ATMs daily and by now they would have found the surplus against their records for that day. Is it so difficult to return what is mine??????