But what if the daughter calls the dude - from the store (so the store's number shows up on his caller ID). Tells the dude that she heard he'd called asking for her, and was just calling back to see if there was a certain item at the store he was looking for or that she had been trying to help him find. Let him know that the store is keeping his name and number - because they want to help him as a customer - and that they know she should get credit for any purchase he makes.

She gets to tell him that his identity is now known by the store. It's kind of empowering for HER, because she's the one doing the talking. She's telling him that she's let others at the store know about his connection to her. And it doesn't come across as a paranoid person accusing him of anything.

Just a thought.