servicing the transmission

The book on my tv says to service the transmission and the transfer case at 50,000 miles, so with 50,585 on monday i took it firestone for what they call a transmission flush, and replace the outside filter, cost estimated $272.00, ($125 cheaper than the dealer) down side is they don't do tranfer cases. when i picked it up and they were writing up the bill i asked how do you flush the trans.? and the service guy says we don't flush them we just drain and fill and replace the external filter because our hoses are to small to match the hose connection so we had a miscomunication and then after he finished typing and the bill printed out he said sign here and because of the miscomunication the final cost is $000 because thats not what i asked for when i set up the app. So my question is a drain and fill with relpacement of the outside filter ok for another 50,000 miles ok or should i go in for a flush, tv is 5 yrs old and out of warranty. you can guess what the chevy dealer said when i talked to the sevice guy there.......

I'd call it good.

I think you should be OK with what was done. Having said that, if it were me, I'd have it flushed properly in two years or 20,000 miles.