bought an iPhone, AT&T says under payment plan, What to do?

[vs2929]

So I recently bought a iPhone 7 plus from a seller and in the description he says he checked the item via Swappa's esn checker and it came back clean which is true. But when I type the imei into the AT&T unlock page it gives me the message "Looks like you havent paid your phone off yet, please pay it off and wait 48 hours to try again".

I asked for a return and the seller said ok but which option in the drop box should I use as the reason for return?

[southern*sweet*tea]

Not as described

[dtexley3]

File a return request ^^^^^^^

[jame234]

Click on Return Item and give reason: Item Not as Described.  Four days later if seller does not issue a return shipping label or refund, click on Ask eBay To Step In and escalate to eBay for help.  Do not let case expire and do not close the case without a refund.

[labs118]

@vs2929

There is no not as described so if they listed it as clear phone with a clear IMEI you need to use
Doesn't match description or photos