Pathetic service from the front desk

Visited lancet in Overport Durban this morning. Terrible customer service at the front desk. At arrival my mother who was having her bloods taken was told that it would cost R150 which she agreed to but payment was only supposed to be done after the first one was complete . Once this was done I went to make payment and the guy who was assisting me seemed unsure what to charge but eventually told me I had to pay R251, so I paid thinking that the type of test might be more intense than we expected. He said that he would give me the invoice in a few minutes. Some time went by and still no invoice. So I went to ask for it, then he says that he charged me incorrectly and he was going to come to me for my banking details. What bothers me about this is the fact that he didn't tell me what's going on. Until I asked for the invoice. If he told me that at the beginning I wouldn't be as upset as I am now. I got no apology for his mistake and I was vaguely told that I should be refunded in a week. That's absolutely pathetic service. It makes me think if I hadn't asked for the invoice he wouldn't have bothered to tell me that he charged me incorrectly. This is unacceptable. It's actually sad that I have to write this review because the nurse who saw to my mum was absolutely amazing.