Mica Emmarentia Customer non-service!

It is my observation that MICA Hardware in Emmarentia is dysfunctional. I bought some painting supplies from them and went back a couple of days later to get a furthe tin of paint. They were out of stock, that is not my issue. The attendant said that he would have the stock in store for collection on Tuesday. (This was a Saturday). So I asked the painters to come again the following Saturday. I went on Tuesday, no stock, so I gave them my *** and asked for them to call me when the paint was there. They called Wednesday just before lunch to say it was there. I pointed out that it was easier for me to collect the paint on Thursday and they indicated that they had put the particular colour aside for me. Well, I went in on Thursday, just after 09:00 to buy the paint. No stock. Apparently they had ordered the wrong colour. I ordered a colour called Windsor Green and they ordered a different shade of green (Which had been on the shelf every time I went the store, as I always checked the shelf). There was a lot of running around, no actual dealing with the situation. So I asked them to call me with a solution as I was doing other shopping. However, soe 4 hours later, I have not received a call. Additionally, I tried calling the store three times and in every instance, the phone gets put down. Nobody seems to want to deal with customer complaints. I contacted their so-called head office and asked for someone in authority to contact me. Same issue, I could seemingly wait forever. My basic question is, what is so difficult when it comes to basic customer service?