some tips i always use when i try to get stuff i'm not technically supposed to get:

-be extra nice to the agent
-have your kids be well behaved (perhaps even "hidden" under the high counter if possible so they're not that visible)
-try to get a guy, since it's my wife's theory that guy service agents are actually nicer than girl service agents
-if it's a girl agent, you speak to her; if it's a guy agent, have your wife ask.

good luck!