I was here(about a week for a conference)

I was here(about a week for a conference)
and just checked out about a minute ago. Went down to place all ny luggage into the car when notice, my phone was not with me. So i went back to the hotel lobby to ask for helping searching out my phone. I realize i couldn't go back into the room because i had checked out. So i asks the front desk lady to help. She said she'll call someone to go into the room i had stayed to look for it. 2-3 minutes i was waiting. Since im going to the airport for my flight back to texas. Id come back to ask front desk for help again. She said they couldn't find my phone in the room. My feelings tells me it is.
So i request help from the manager or anyone else to help before im late for my flight. Waited another 3-4 minutes or so. No sign of anyone. I was anxious, so i just left and find my own ways. Ive asked my family to keep calling, while i go back to the room(standing outside) and listen if it rings.
Indeed, i could hear my phone with a familiar ringtone of mine. Thank God there was a lady who work there ,so i asked her to help open the door. It was under the sheets.
I understand if the lobby was busy, but i was the only one(and another person, but he left a while back).
To me this is unprofessional, had i didn't go back and check or if that lady didn't walk by. If i had waited for the hotel to assist, then i would have been late for my flight.
Marriott needs to reevaluate and check your professional work ethics, to get more business is to consider your guest's needs. If their needs are met, most likely they'll be back for more, because they know you CARE.