Bad Communication with promotional items

Dis Chem has a promotion - when you buy 10 packs of Pampers you will receive one free.

With this said my wife and I Purchase 10 packs and may I say we swipe our loyalty card every time and we buy a pack every month. When we enquired about how many packs we bought they said it was 10 packs.

Asked about our free pack they said they sent a message on the 26 March 2020. I said that we didn't recieve the message or even if we did we must of over looked it!

Point of the matter is they said we should of collected if it within 60days. My argument is we buy a pack every month if it's in your system why couldn't you give me it to me free then. Also they don't have an answer when you ask then what's the reason for the 60days?!

I will certainly not be back there.

Also we get their emails on promotional items why couldn't you send us an email or a reminder that your 60days is almost up. We feel so ****** by dischem