Organic juice bar is using Silk brand almond milk, pouring it into their own bottles, claiming different ingredients on bottle.

If you are accurate, then no it would be illegal. You can report this to Silk and let them take the appropriate steps.

This question is more appropriately directed to civil litigation or government regulation.

Based upon the limited facts presented, it sounds like this is definitely illegal. Silk attorneys would definitely be interested in finding out more, and should be informed, as there could be claims of trademark infringement and unfair competition, generally.

Yes, this is illegal as well as an infringement. This seems to be a violation as well as a misrepresentation. jacobsonfirm.com