can't obtain code for student/teacher adobe purchase in store.

I have tried everything including 2 online help chats that still have not helped at all I was finally given a code that doesn't work.

so now this was suppose to be a simple process... I purchased instore the Adobe Acrobat Pro DC (student/teacher) completed the online form with proof we home school (2 time now) but every time the case is close with no code???? I have tried calling but I am transferred from depart to depart that tells me to go back to the store I bought it from but with the student/teacher version you apply for a code you don't just get one. I tried online help chat first one lasted 1 1/2hrs finally got a code that doesn't work "invalid code". tried the online chat again but after 45minutes it thanked me for my time and ended chat. Please can anyone help