Charged for new components and fitted with used downgraded components

"PLEASE BE CAREFUL AND ENSURE THAT YOU RECEIVE THE CORRECT COMPONENTS AS CHARGED WHEN SERVICING YOUR BIKE AT CYCLE LAB FOURWAYS." I've bought 4 bikes over the last 6 years from Cycle Lab Fourways and have alwats been happy with them and have trusted them implicitly with servicing our bikes, up until last week. Sent my bike in last Sunday for 3 spokes to be replaced and a minor service. Was called by Philemon on Wednesday, who mentioned that my hub was damaged, he had greased it but recommended that I replace in the near future. I asked him to rather go ahead and replace the hub. Fetched my bike on Saturday, all good up until i noticed yesterday that the hub fitted was a used Deore hub and I was charged for a SLX hub. Took the bike back and politely asked for them to rectify the error. This morning I get a call from Philemon saying that they charged the wrong PLU. I said to him that the hub is used and I'd like the correct hub to be fitted. I later get a call from Johan, who then says that the bike was fitted with the correct SLX hub, I was meant to pay R1500 and they had discounted and charged me R1100. I asked him why was a used hub fitted, he then said that they used my old casing but the internals were new components, I refuted this as true considering they had returned my original hub and all other spares when I initially fetched my bike. He then called me back and said that they can offer me a refund in the form of a gift voucher to spend in store. I refused and asked for them to fit the correct hub. I paid R36000 for my bike and am baffled why a R300 component was installed. Johan is now looking to source an upgrade for me. I am left wondering how many of us have been ********** by this sort of overcharging and under delivering?