On one slip, three prices incorrect

I bought a few items at pick n pay mulbarton.When I checked my slip I noticed that three items was incorrectly priced.i spoke to the manager. The items were: parmalat cream, bliss yoghurt and a potato peeler. I have paid R18 more on these items than the pricing on their shelves. He came back to me and told me that - yes the cream was incorrectly marked. The yoghurt he said he does not know as I took the last one????but the price is flashing where the item was and that the peeler was moved and I had the more expensive one( nothing was moved, they were all hanging in a line by the flashing price.He then proceeded to tell me to fetch my shopping in my car so he can swop the items and check and so on. He had no customer service as I had already stood there for 30 minutes and that shop is busy. I phoned your customer service and until today no-one has come back to me. I phoned again and she said some team will phone me. Again nothing. My question is if I get R18 ****** from me, how many people do not check their till slips and this happens. I mean on one slip three items was incorrectly priced. I AM VERY disappointed in your service Pick n Pay.