Chevy/GMC DEF tank trouble

Traded my 2011 GMC 3500 last winter for a 2016 F-350. Nox sensors, couple DEF tanks, Last time it was in the shop they replaced the DEF tank, I drove it 70 miles and check engine light and poor quality DEF was on again. All of this in 40K miles. Traded it before the sun went down the day the dash lit up again. Alway been with GM trucks until this 2011 DMAX, not again any time soon..... Bad enough when you got legs to walk but when it go's to limp on I-40, 97 degrees, loaded with show horses and I'm in a wheelchair, then I had to go a different route. We got two 6.7 F-350's and not a minutes trouble out of either. One truck a SRW with 3:55 gears the other a Work Truck with Max tow package, DRW and 4:30 gears.