Indeed. It sounds like a scam to me, too. I'd be tempted to report it to my telco (who probably can find out who called, despite it being witheld).

Quite apart from anything else, why would a legitimate curry house phone when a curry was ready for delivery in any case? And why would they not identify which curry house they were?

I can see the trick working on households that are more easily confused, especially ones where several people share the phone line.