iff is based in Paris and has not seen any.

This means that it is unlikely that a visitor to France will randomly come across one of these bottles.

As you seem sure that this sized bottle can be obtained you may need to do some more leg work.

Have you contacted Danone directly?

If they are not able to send you 3 empty bottles, perhaps they can forward you details of vendors. This information would make it much easier for someone who was willing to help you to do so.

Merely repeating your request here isn't very useful.