Retrieve lost data

I was in a T-Mobile store in Golden Valley Minnesota and purchased a new iPhone 11 my iCloud storage was low so hang backed up in 2 years I purchased more data for .99 backed up all my data fr that phone after purchasing additional data the guy then starts setup on my new device the iPhone 11 and says ok it’s backing up so I will factory reset the old iPhone XS while the 11 is backing up I said are you sure my photos are all I care about he said yes it’s saved to iCloud no worries well I get home plug the phone in and I have no photos please help me retrieve those photos.?!