Mastercard complaint: Wrong information at Lounge

I am a Dragon Pass member (Membership no. 7387 1100 0005 5811). At Toronto Pearson International I was travelling by Lufthansa (Flt no. LH0471, date 13.7.22) and at 15.35 hrs, the Person at Reception – Mr. Navin – informed me that my Standard Charteted World card (issued in Bahrain) is not accepted at Plaza Premium Lounge, (Terminal 1), as the Lounge accepts ONLY Canada issued cards. I went out checked the Dragon Pass app found the Lounge listed. I went back showed Mr. Navin the app. Now, he stared making excuses trying to divert the issue, saying I will be charged as I have a guest (my wife). I told him that my wife is an independent Dragon Pass member. At that, he said sorry allowed me access.

Sorry is not enough. Either Mr. Navin is ill-trained or for some obscure reason of his own, he unilaterally decided to deny me access and humiliated me in front of other passengers.

I strongly object to this kind of behaviour, which damages not only my own reputation but also that of the Lounge, the Dragon Pass brand and MasterCard.
I am bringing this to your attention and requesting you to take appropriate remedial action.
Thank you