My car has always blown cold only after a few minutes of overcoming the heat... I live in SFL so I get 80+ degree weather more or less year-round, every car I've owned/driven/ridden in has been this way.
The fact that your car blew cold immediately before having it serviced just sounds coincidental, Oct-May is mostly cooler temps with fall/winter being the majority... not to mention maybe lately you haven't gotten the shady spot at work (if there's one to be had, not for me there isn't)
That's all I can think of, really. Unless you add a remote start to the car and turn it on while you're still inside getting ready to leave, there's no way I can imagine that the car would be able to immediately blow cold air.
2012 SGM SEL Sedan 303a w/o Nav | Job 1 built 6/2011
FSWERKS Cool-Flo w/ ITG Filter | FSWERKS Stealth Exhaust | 17x7.5 Axis Sport XMX Graphite wheels
Sonic Crew #28 | Rally Revolution #117