ATT wireless Bad warranty by ATT Nationwide

I sent in cell phone to ATT service.They sent a defective refurbished phone.

I went to service center Advised they would have replaced same $190-200.

I was sent original phone back saying warranty would not apply due to damage.

I went back to center they advised replacement had balance of original warranty (3-4 weeks approx.)

I was charged $595 for a refurbishe phone that doesn't work properly.I am a corporate account,have had for

20 ++ service now They won't honor a bad phone that did NOT work after 3-4 weeks.

I will go elsewhere what ashame and scam. "No one can help me".