Sit down on a call with them do three things:

1. Have them explain to you their understanding of how product/service works and is used. Take note of where there are misconceptions or misunderstandings.

2. Explain the product/service again yourself, but highlight the areas that they didn't understand, and walk them through it.

3. If possible let them experience or use the product/service so that they can see how it works firsthand.

Chances are that it's just a failure to communicate clearly on both ends and to identify the gap in understanding between the two teams.