A rotten apple at Clicks Kempton Square

I've been to this particular Clicks numerous times before and have always received good service. On Thursday however I was very disappointed. I came in for a self prescription and as always, I take my number and stand behind the queue next to the aisle. Close enough to see what's going on at the counter and to hear when my number is called. I stood at the same spot and a few of the staff at the counters glanced over at me including the guy that assisted me: K**** P********** A lady who had been waiting for a long time decided to leave and she was number S203. I was S204. KP called S203 over four times and when he realized the customer has probably left, he then called my number. I immediately bolted from where I had been standing to the counter. When I got there and greeted and started telling him what I needed, he cut me off and said he had been calling my number for more than 3 times, if I'm going to take a ticket and disappear, I need to enter my cell number so I can get an sms. I explained to him that my number is S204 and he called S203 numerous times and I saw a lady leave and I guess she was S203. I could see by his reaction that he realized his mistake but instead of apologizing he continued with his foul attitude. I was there to take medicine for my child but am not the main member..I had taken medication there before with no issue, he wanted to know what proof I have that I'm the mother of the child. I told him I didn't know I needed proof and had never been asked for the proof before. He asked for my child's surname and date of birth. I told him the day and month and because I was already annoyed by him(and the fact that i have 2 other kids) I needed a minute to think about the year. My mind was clouded at this point and I had to calculate 2023-4 years...as I was doing this he sarcastically says " and you are supposed to be the mother of this child yet you don't know the child's date of birth" I was furious and could've punched him in the face! This guy had put me off of this particular Clicks and it's rather sad because I have always interacted with great staff there. One bad apple really does spoil the whole box!