Like @PurpleFog said, they obligatory have to pay PRO royalties. even if you’re not registered in PRO. Give them your name with surname and track title and ask for the name of the campaign and brand so you can find those royalties in the future.
So it’s your choice if you want to get them from PRO by registering your music or not.
Here is a wider insight about PRO: The AJ Community Guide #2 - Performing Rights Organisation Royalties (PRO)