I can vouch for the purchasing process with them! I just purchased something from the 23B collection from them this week. I reached out last weekend about the new collection. Because I wanted them to source a unicorn and it was something they didn't have in hand, they required a deposit. They told me their price with 3-day shipping included, they only accept Zelle for domestic (USA) customers btw.
They were super responsive and were able to get me something fresh from the boutique when it dropped on Tuesday. They took a photo of the item while they were at the boutique and I was able to confirm if I wanted it or not. Then they got it shipped to them from the boutique instead of taking it home due to security concerns. I asked about tracking info and they told me that it wasn't provided to them. I thought that was a little odd but I did some research and it seems like some Chanel SAs don't provide tracking? They communicated that they should receive it within 2-3 days.
Once they received it 2 days later, I was sent many detailed photos of the item so I can inspect the quality and it was perfect so I OK'd it! They also sent a photo of the receipt at this point which they include in their full set! From there, I purchased package insurance and express overnight shipping for an additional fee because I wanted it sooner haha! They also told me that they often recommend that their clients do "hold at fedex" location so that the package for sure doesn't get lost or handed to the wrong person so I opted for that too. They shipped it the next day, and provided updates every step of the way. It's on its way to me right now so I can update later when I receive the item