seeking reliable/legit auto shop(s) that does tranny fluid "flush"

[blue mountain raider]

hi my 03 ford focus zx5 (auto) is pushing 83000kms. got it used at 79000kms. not sure if tranny fluid was ever changed. dont wanna take the chance. i read that a tranny fluid "flush" is better than just changing the fluid.

anyone knows of a good shop that does this well? a shop that actually does what the customer asks.

dont wanna go to ford stealer cuz they would overcharge me for sure.

thanks.