Unfairly charged for access

I am on FNB Rewards Level 1, I have both a Platinum Cheque and Credit card account. I have used the SLOW lounge many times before in the last year without being charged. I used the SLOW lounge in Jan with my 2yr old son (first visit of the month). I was charged R500. When I queried this with my private banker, Lisa, she said that maybe it was due to the fact that when I downgraded from Private Client to Platinum a year ago (both acc's are now Platinum), the bank advised me I could still use my existing cards - thus my accounts are platinum but cards still look black & not silver. 1. Why was my 2yr old son charged R250 2. I do not think it is fair to tell me the appearance of my cards don't matter and then down the line, I get penalised for it when I cannot even find in the fine print that this is an issue. I have since ordered new cards but I would like the R500 refunded!