1. Where did you book your seats?
2. Did you book them in one transaction?
3. For which train? (route, date, departure time)

1. Where did you book your seats? Eurail website 
2. Did you book them in one transaction? Yes
3. For which train? (route, date, departure time) Turin to Paris, 29/Apr, 7:36am

If you booked them in one transaction, then what makes you think they're not next to each other or facing?

OK, that's convincing. I just did a test booking and got seat 75 and 78 (don't remember carriage number) so it's not yet so full that it's not possible to sit together.

You could try:

• Customer service. Mentoin your travel date so that can prioritise correctly.
• SNCF by phone. Press #85 for English. I don't know if they can access your booking though because it was booking via Interrail.
• Ask on the train if anyone can swap seats.