Worse Customer Service at Canal Walk Havaians

On 30 November I bought 3 kids Havaians online (2 for girls and 1 for boy) unfortunately when I got the order the boy did not fit so I wrote an email to request an exchange. I was given a choice for collection or take to store and I choose Canal Walk Havaians but when I got there I was helped by this lady with the worst attitude telling me I can’t exchange because I bought my item online prices are not there same and she was telling me the size I was looking for which is a 2 they don’t sell in store for shoe I was asking for but online they did so I told her I will pay the difference( she knew I will report this and she said she was going to do a favour and call someone so that they can give it to me on the same prices). Please teach your staff not to talk back to Customers and have the best customer service. By the way she ended up giving me shoes she told me they were a return from another customer( I was not happy with those shoes but I was just tired of here attitude) All of this happened on 6 Dec. She might have underestimated me but I used my money to buy there, I did not borrow money from her. Worst customer experience ever