Sasol garage Put water in coolant tank

Good day

Sunday 5th January 2020, around 8:30 am ; I went to Sasol garage at Monavoni centurion next to mall@55 as my car needed coolant

Guy put in anti freezer then added water which I wasn’t aware then that it was wrong

The car over heated 5km away from the garage and required me to switch it off ,

Called bmw and they towed it to menlyn auto They fixed it and it was ready for collection on Wednesday 8/01/2020 and was told that to never put water in the coolant tank nor use anti freezers from garages

And cost amounted to R4200 , Got receipt for proof

I want this matter to be given fair treatment as the garage attendant costed me money