When filling a hole with loose earth, should there be extra?
They should have compacted the fill in shallow layers to speed up the settlement, in which case settlement would be essentially done in maybe a year. 
If they just filled the hole, that will take many years to fully settle, and there isn't much you can do from the surface now. 

For loose fill, that's probably about the amount of soil you need for it to eventually be level and not leave a dish in the yard. 

Unfortunately, you'll need to rethink your patio plans. If they didn't compact it in layers, anything you put there in the next many years will seriously settle and be a mess.