What happened to my marshmallow 6.0 upgrade?

[AC Question]

I recently downloaded and installed marshmallow 6.0 on my LGMS330 otherwise known as the LG K7 which originally was running on lollipop 5.1.1 when finished installing the phone shut off and restarted just like it was supposed to however when the phone turn back on I didn't notice any changes so I went to settings opened the "about phone" file, then opened "software info" and checked Android version and to my surprise it was still on 5.1.1, so I went to my update file to try to reinstall however where the ooption for "install and restart" should be there was nothing so not only did my marshmallow not install but it took away any chance of me getting the update. what happened?