Con artists

This morning around 9am I went to your branch in century at the shell garage to but a streetwise one pap. I gave the lady R200 and she gave me change and it was crampled up together. I just put it in my wallet and went to the next window. Now I'm at work, wanting to buy lunch, I notice that she only have me R80 change. I was ****** of my R100. I didn't check because I always trust your staff. Not to mention that the pap was undercooked and soft as morning porridge.Please get this sorted