Could I be wrongfully terminated??

[collen13]

Hi, I was fired this last tuesday because they said for my attendance, but back in march of this year my asst. manager told me to get some intermitte medical leave papers filled out by my doctor because i was missing days due to my bronchital asthma. Even though I had doctor notes, she said that walmart does not except doctor notes. I was told in April that my papers were approved. Than come end of September a different asst. manager asked me if I had completed the medical papers, if i had copies of them and what manager did I hand them into, because these papers where not in my file anymore. The asst manager I gave them to had transferred to a different walmart, but i brought in copies that i had from home and gave them to the asst manager that had asked about it. This month they had hired a new asst manager and this tuesday of this week, he called me into his office to say that i was fired due to attendance and that my papers were never approved. The only thing I not understanding is how he could say it wasn't approved if he wasn't working at the time it was and especially if the approved original copy was some how taken out of my file. Any advice would be appreciated. I am trying to fight this by calling the regional manager of that store and the home office of walmart.