I would suggest you go back to the store with a tape recorder in your pocket. Tape all that is said. Then file a complaint with your Attorney General of your state. Provide them a copy of the tape and all proof that you have this service plan.
you can also get a spy pen that will record. Put it on your lapel. I would love to see the expression on that managers face when he gets fired. You must hide the pen so it there but recording. This manager must think he is some kind of goddness or something to laugh at you.
I bet that walmart will worship the ground you walk on once you file a complaint.
I do not shop at Walmart. I use to. They got greedy and nasty. So Now I boycott them and I spread the word. Suffer the consequences --Nastymart or Nazimart.
To all you puppet on the strings that don't like my rebuttal. That's to bad. May Nastymart go bankrupt. Please report back so I know whether my advise is working for people.
Good Luck
Nathan