I'm sorry, but it is very hard for me to tell what it may be from those pictures. I'm confident it isn't ick, but from the pictures I cannot say it's columnaris either. Although the talk of stringy white stuff floating around and globs makes me think it still may be. I'm not very experienced with Betta diseases and treatment, so hopefully someone who is will chime in.
Donna - You do bring up a good point. I can relate to having the "rescuers" mind. Betta's are cheap to the big corporations that get them from mass producing mill breeders. That is one of the big reasons they don't put much effort into proper care and don't make a big deal over Betta's dying on the shelves.