Hi JIGSAW1234,
Thanks for posting in Apple Support Communities.
We understand that your emergency phone call was not placed when you fell. This could occur if your Apple Watch or iPhone did not have a signal to dial out. If you do not have cellular on your Apple Watch, maybe your iPhone was too far to make the connection to complete the call. We would be unable to pinpoint without additional information. You may want to check that you have Wi-Fi Calling enabled on iPhone in Settings > Cellular.
Use Fall Detection with Apple Watch - Apple Support
Make a call with Wi-Fi Calling - Apple Support
Regards.