Shoppers Drug Mart complaint: Very rude and bad Customer Service!!!!!

Today I went to shoppers with my nanny to get some daily necessities for our house because I got the email last night regards the promotion for 20 times points if you spend over 75 dollars. I bought some body lotion for $39.99 Olay face cream $32.99 and a Olay face wash $9.99. When i wanted to cash out i saw there was other customer who was cashing out at the cosmetics cashier there so i walked toward the general cashier counter because there is no people line up. A young asian male cashier who serviced me, he scanned 3 items and told me total is $104.85 he asked me if i pay cash or card i told him im going to pay with cash. I also asked him if there is 20 times points if spend $75, he seems did not know about the promotion because he asked me back “really?” Then walked around to check. However, he did not really found it out. I told him it shows on my optimim card. He answered “oh, if it shows on your card then you will have it” After i paid i was looking at the receipt it showed the Olay face cream is $42.99 (the originally price. I found out the price was wrong because now it is on sale for $32.99 i told him right away. He asked me what price instead he checks the price by himself. After i told him the sale price he did return and give me back the money and purchase again. I suddenly remember i will not getting the 20 times points because he made 2 separate transactions so i told him please refund everything then i will make a new purchase transaction with correct price. He started his bad attitude right after i told him to do so. He started talks about i shouldn’t use cash and i shouldn’t cash at this counter i should go to the cosmetic counter to cash out blabla. I felt he was very frustrated and sounding very rude and i told him to refund anything. He suddenly closed the cash drawer very hard and loud. My nanny and i were so scared. He seems like wanted to beat people. Then he used the phone to call his supervisor come over for help. The supervisor came over did not talk too much and told him to take a break. The supervisor was helping me to finished the transaction, however, when i walked to check the price of the face cream and walked back i saw the supervisor was whispering with another cashier and i was just at their back. I asked them if they can talk about me after i leave the store because i think it is very rude. She answered me that other colleagues just wanted to know what happened. I told her they should not whispering when i am still in the store! They are not professional, respect others. I really want to let your company know about how your employees worked in store at the front line and how they provide their services towards customers because they represent you and your company. I hope the shopper could take the complaints seriously to provide some coaching to your employees.