Alarm sounded for 13 minutes no call from monitoring

Hi all, Hoping someone can explain why the other morning my Ring alarm went off and was ringing for 13 minutes but never received call from the Assisted Monitoring ? Received email (which went to my PC but that is of no use really) but really need the phone call. As only just installed this and on 30 day trial wondered if that has anything to do with it (have entered my contact number in the app) or is this something only available in US and not UK (I know professional monitoring is only available in US) As far as am able to read I am supposed to get a call (no idea how long would have to wait though but after 13 minutes would appear to be too late as who knows what could have happened to me by then) Thanking in advance for any help