Can a deleted feature service in arcgisonline be restored or retrieved?
Not going to happen for me. There is good news though. As crazy as it sounds, There was only one feature service on a web map we used to collect GPS points using Collector. I opened that map, the data was still there. I saved it as a layer, put it into ArcMap, exported as a new shapefile, put back into existing DB and published a new service with the same data. We only lost a few days (very few points). We also had a back up of points that were shot that we were updating. So this wasn't the end of the world. After it happened, just wanted to see if the first way would work. I use the settings mentioned above for services that I have created that need to be protected. Lesson learned,,,,,,,,,,,,,,,check all settings on all important services!!
I am not sure that it can be recovered. There is no "Recycle" bin for the account.
I would recommend creating a technical support case and have the analyst team see if there are any other options available.
Although I haven't encountered this problem yet, I worry about it happening. I'd be curious and appreciative to find out what the answer is if you contact tech support.
One thing that could be done is to enable delete protection: Item details—ArcGIS Online Help | ArcGIS
There is also a blog that talks about this very subject: https://www.esri.com/arcgis-blog/products/arcgis-enterprise/uncategorized/protecting-your-arcgis-online-items/
Yes, I *Always* check the delete protection option for practically everything I create in ArcGIS Online. My worry is that, even with that protection, an accidental deletion could still happen. Also, I've had experiences where users ask if we can restore a previous layer version because they accidentally deleted data they didn't mean to. Seems the best we can do now is vote for this Idea of an "Auto Backup" process.
Maybe another attempt:
Try ago assistant (https://ago-assistant.esri.com/)
to see if a service definition file exists for that feature service.
If it does, view the definition's json to see if you can use the settings to re-make the feature service.
Retrieving data ...