SPAR charging double the going rate on products!!!

I have recently exchanged 3 of my Soda Stream 60Lt gas bottles at the SUPERSPAR in Sasolburg and was totally shocked to realise that they charge double the going rate for the exchange and only offer half the going rate for the empties. On Monday 13/09/2021 I have raised a complaint on SPAR website and was actually surprised to have received a call from the Customer Care department. Apparently the National Pricing Manager for the Vaal area would investigate and come back to me and its now Thursday 16/09/2021 with no reply. It is sad to see a national chain store robbing customers like this and empty promises without coming back to them or to complete an investigation as promised.