The thread starter only needed .2 quarts. Just about ANY new ATF or additive could've been used at that dosage.
Mobil 3309 is available at some of the lubricant distributors and rarely(never) seen at auto parts stores. But, those oil distributors will always try to sell you a case or more.
Buying at the dealer??? WHY? There are plenty of similarly or better performing fluids at reasonable prices available. I wouldn't have bought the 1st 3 quarts there to begin with.
Some dealers' parts departments aren't open on weekends, holidays, and are not open as late as the local auto parts or department stores.
What year and vehicle is your A246E in?