Consistently bad service

I went into your new store in Waterstone Village today - after not having been in a Clicks for a long time. Consistently bad service for Clicks. When the cashier rang up the order (Shannon was her name), I thought the total looked too high and I asked her to check that the 3 for 2 special had come off. She said it had but didn't show my anything on the screen. So I paid and then when she passed me the cash slip, I saw that the cheapest item had not come off. So she had to call a supervisor to credit that back into my credit card. No apologies, nothing. And then they wouldn't give me back my cash slip!!! For crying in a bucket - what if I need to take something else back at a later stage? Shocking shocking shocking. Back to Dischem because Clicks have learned nothing over the years.