"Collaboration Complete" is an automatic message in your brand chat. It is sent by the system when a partnership is closed out on onbrand — for example, after your verification or an exemption request was approved. It does not confirm that the brand delivered the products or will send a replacement.
onbrand doesn't make fulfillment decisions for brands. If the products never arrived, you can message the brand in the chat, and you can apply to other brands for your future events.