Air in pumps.. Paid for petrol I never got..

This evening around 20:37pm I drove into the station to pour petrol in my vehicle that showed me 5km meaning I had 5km left to drive to fill up... When the petrol attendent poured R50 the kilometers went from 5 to 4 Kilometeres I asked him how come he couldn't answer he just said he did pout petrol.. I then asked them to pour another R50 I waited hoping it will atleast give me more kilos to drive no instead it just sat on 4 kilometers I complained to the guys that work at that station Marimba Gardence filling Station by Sebenza in Vosloorus South African they couldn't answer me instead they refused to give me the owners or managers numbers... Elliot one of the attenders told me to call their land line the next morning the manager will be around. I drove home the kilos went down to 3 then eventually to two i got home tested if the landline worked it to my surprise it wasn't every time I call it says number is busy.. I then drove to the garage again to ask for the right number they gave me another filling stations number telling me to call at 8am the manager will be at that station to assist me... I had so much trust for engen infact that's the only filling station I use today experience has made me doubt engen never again will I ever waste my hard earn money on buying petrol at engen..