$25 charge for SIM card Replacement? Is it true or the representative put the money in his pocket?

Hi Community,

I'm switching from iphone4s to iphone6. As you know, the SIM card is different, so I have to replace it.

I went to a AT&T location, and the representative charged me 25 dollar for it. Cash without receipt. He told me its a one-time charge, if I come to replace another SIM card in the future, it's gonna be free.

I'm not the holder of my family plan, if it is a reason for that charge.

$25 charge for SIM card Replacement? Is it true or the representative put the money in his pocket?

A Confused Customer