Bests & Worsts Reviews from Amazon

I've enjoyed five years of Facebook Messenger until recently when the Messenger team sent me a note on Messenger stating this version is outdated and isn't compatible with my Amazon Kindle fire HD 7. I can no longer send or receive messages. The note instructed me to load the updated version of Messenger or Facebook Lite... I can do neither because the suggested app store where these two are located isn't supported on my Kindle Fire HD 7. I've tried everything short of a system restore.... but if the Messenger App I was using is outdated... it wouldn't make much sense to do a system restore anyway. Have went to Amazon and Facebook for help and no resolve. Very disappointed... all I want is my Messenger back.