Terrible service from an arrogant till jockey

I have been a loyal customer of RO systems Sunningdale since they opened. About a year ago I got a 25L tank that consistently appeared to be an issue . I could never get it filled because of the apparent timing either too early to produce water or too late. So granted on a few occasions I couldn't get it filled completely due to rationing and I completely understand that everyone needs to get water. Two Saturdays ago I enter the store with an issue with water amount , this time i'm given the opportunity to fill the tank but an elderly lady behind me cannot get her ration if i fill my tank. (Evidently I can do this because i have my two small kids with me) Nonetheless , I offer to have half the tank filled in order to give her some as I am well aware of the frustration at this point in being a customer there. I return the Sunday and apparently there is some sort of electrical issue so the pumps don't work. Fine , no problem these things happen. We do our shopping and as we leave I decide to take a chance and see if it's working. My wife takes the tank I pack the kids in the car , after a while she comes back furious. The male at the till ( who only seems to work Sundays and has such a disgusting attitude towards customers) didn't fill the tank up to 25L , when my wife questioned him and said we always have the tank filled to the top - he had such a stuff you attitude that he made a point of filling the tank just to the 25l line. It's not about the extra few milliliters but that brazen stuff you customer you are dependent on us attitude that is sooo bad for business. Could you tell me is he the owner of the store ? One would would swear he is , and even then it is unacceptable. I have had the displeasure of being in the store on a Sunday before and seen how he interacts with customers . He truly is bad for business , I will no longer use your store it was very convenient but I have moved on . 25L x 3 per month with bottles for baby estimates to R1440 per annum that I would have spent at your store. It won't break the bank but how many customers have you lost already that haven't complained about this arrogant , ******** chop.