Sadly the Vancouver boutique is very well known for having bad SAs. I'm in Vancouver and own several Chanel items, but I've only purchased one or two from the Vancouver boutique. None of my bags were purchased here; that's how bad the service is.
It's completely normal practice here for the SAs to not acknowledge you, sadly. You need to specifically ask someone for help, and they will just show you what is available and there's no opportunity to ask for other stock, especially for SLGs, as what is shown on the tray is usually what is available in the store.
The Calgary boutique has much better services, if I recall correctly. You'd have to order over the phone and they can ship it to you. I think the shipping isn't free but don't quote me on that.
I completely understand you when you say it makes you not want to buy from Chanel. I try not to deal with the Vancouver boutique, and if I want to buy something, I either go through my personal shopper or I try to find from elsewhere. I used to try to ask the Vancouver store, but 9/10 times they don't have it and they won't try to help you find it, so I don't even bother.
Keep in mind that there are a LOT of very wealthy people in Vancouver, those who will buy a TON of stuff without even looking, and there aren't that many Chanel boutiques in Canada, so there's almost no competition for these SAs. They have zero incentive to help you.
meant to reply to this post in my last reply whoops