i thought that if i'm their currently client. i can request an unlock on any iphone i want.
You thought wrong.
Read the details below:
General Eligibility Requirements for Unlocking iPhone
AT&T will unlock an iPhone under the following circumstances:
•The person requesting the unlock is: ◦a current AT&T customer or
◦a former AT&T customer who can provide the phone number or account number for the account
•The iPhone was designed for use on AT&T's network;
•All contract obligations, including any term commitment, associated with the device to be unlocked have been fully satisfied; and
•The iPhone has not been reported lost or stolen.
Additional Information about iPhone Unlocks
Current customers will be allowed five (5) unlocks per account, per year, so long as their account is in good standing with no past-due amount or unpaid balance and has been active for at least sixty (60) days.
Former customers will be allowed five (5) unlocks per former account so long as they owe AT&T no Early Termination Fee or other unpaid balance.
In addition, AT&T will unlock an iPhone for: (i) an active and deployed member of the military who is a current AT&T customer in good standing and is able to provide AT&T with deployment verification; and (ii) a person who purchased the iPhone from an authorized location at the "no commitment" price and can provide proof of purchase.
iPhone Unlock Requests
Requests may take up to 5 to 7 days to complete.