user: Upgraded to economy plus. Won't assign seat forSecond flight. Shrug &amp; say it may be a middle seat. What did I pay for? #Deltastinks
agent: Hello, Sonia. Follow/DM your confirm # for assistance. *ARD
user: Don't know what confirm # means
agent: Your confirmation number. *ARD
user: My confirmation # H8g4fb. Don't have even a boarding pass for next flight, or a seat even though I paid for upgrade. Not flying Delta again.
agent: Yes, unfortunately, we only have the middle seat via ATL-RIC for Comfort +. *ARD Did you want me to assign your seat? From there you should be able to retrieve your boarding pass. *ARD
user: Just landed. Yes .Aisle seat economy plus. Should have been able to do that before I left.
agent: No aisle seats, only a middle seat is available. *ARD

Customer enquirers about seating in flight. Agent informs customer that only middle seat is avialble.
### Instruction: Below is a conversation between a human and an AI agent. Write a summary of the conversation.

### Input:
user: Upgraded to economy plus. Won't assign seat forSecond flight. Shrug &amp; say it may be a middle seat. What did I pay for? #Deltastinks
agent: Hello, Sonia. Follow/DM your confirm # for assistance. *ARD
user: Don't know what confirm # means
agent: Your confirmation number. *ARD
user: My confirmation # H8g4fb. Don't have even a boarding pass for next flight, or a seat even though I paid for upgrade. Not flying Delta again.
agent: Yes, unfortunately, we only have the middle seat via ATL-RIC for Comfort +. *ARD Did you want me to assign your seat? From there you should be able to retrieve your boarding pass. *ARD
user: Just landed. Yes .Aisle seat economy plus. Should have been able to do that before I left.
agent: No aisle seats, only a middle seat is available. *ARD

### Response:
Customer enquirers about seating in flight. Agent informs customer that only middle seat is avialble.