Lost text messages?

Last night I returned a phone to AT&T and turned it off, I didn't restore/turn on my new phone (already activated in store) until this morning.

I didn't seem to have any texts when it turned on, and I had a friend text me last night. He told me about his text, but is there anyway to see the other texts, or are they completely lost? Where do they go? My friend sent it showed "Sent as Text", but I didn't receive it. I thought I may have received them all once I turned on the phone, similar to when your phone is in Airplane Mode and you turn it back on to LTE and Wifi.

Thanks!

 

Hmm, figured as much. Assuming it's impossible to ever find out if there were texts?

Why are airplane mode texts not lost? At what point are texts not received? The phone was activated, just not setup yet...