Sun City Rules are NOT Consistent

We are staying at Kingdom Resort for the week of Christmas and we have been visiting Sun City in the evenings every other night for dinner or just entertainment. We are travelling as 5 adults (all with Silver MVG cards and a 3 year old). On all our visits except tonight, we were let in successfully for R375, our child was never charged. Tonight Doreen accused us of lying about how we got in the other nights and asked us to produce our previous slips, WHICH WE DID and she still continued to tell us that she can't let us in with my digital MVG card, which had been working fine all week and told us that my son had to purchase a ticket online to enter. If this is your standard protocol then why on earth were we able to enter the resort effortlessly with my digital card and my son for R375 THREE TIMES???? I am upset. My son was looking forward to one more evening of fun before we head home. I need this to be fixed. Doreen was very unpleasant to deal with and very rude.