Mr Price Rosebank - Appalling Service

I purchased a chinos online last week Friday Skinny Fit Chino Pants SKU: ********** 152036 Colour: Mint Size: 34 Reg all well with the delivery but when i got it i found out it was too small so i needed a size 36. today i go to Mr Price Rosebank and was served by Mulweli, i first asked her to check and see if there is a size 36 online if thats the case refund me cash and i will purchase it online as the store did not have a 36. she told me there is none, so i resorted to buying a size 38 as i really liked the chinos and color. whilst serving me a colleague came to chat to her and they continued their conversation after a while i told her i am in a rush as i am on lunch and she than tells the colleague she needs to deal with her customer... thats not all though when i come back to the office i log on to the website and i see the same chinos are available in a size 36 after your cashier explicitly told me there is none online and i resorted to buying a size 38. i am appalled and disgusetd at the level of customer centricity and lies been told to me. i am going to purchase the size 36 online and i want a cash refund paid out to me when i return the other opants