The information on the diseases is good. I'm not sure what that BettaZing stuff is... certainly not anything I've ever seen at the pet stores here. But we will have to head out in the morning and see what we can find that might be similar.
If the antibiotic have been completed I would start her in high dose aquarium salt 3tsp/gal and tannins, water temp 75-76F....the smaller the QT container the better, bare bottom and a fake or real plant of some sort to help make her feel safe, place in a dark or dim lit area and cover the top with something to maintain warm humid air above the water, hold food for now....
Pre-mix the aquarium salt 3tsp/gal in a 1gal jug of dechlorinated water add the tannins to steep (either IAL or dried Oak leaf) shake well before use and use this pre-mixed treatment water for the 100% daily water changes for the next 10 days....
You cannot use high concentrations of salt with Potassium Permanganate! Do one or the other. Potassium permanganate (KMn04) is very good for treating ich and other parasites (it should also kill columnaris...). I would normally choose KMn04 since it is such a bad break out, but she appears very weak and KMn04 kills everything, including fish. Make sure you are following the proper dosing instructions with the KMn04 or stop using it and switch to salt.
Microscopes are a wonderful thing: I got a look at one of the dead colonies that came off when we moved her into new meds/water yesterday morning--and the answer was velvet. Most of them died off in the KMnO4 but we are still treating her very carefully and trying to protect what's left of her slime coat.
She kept beaching herself for a while, and every now and again she'd use the spoon (she swam right in) we moved her with to prop her head up to get a breath--but she's doing better now. She's moved into slightly deeper water, though she's not as deep as she could be going.
Really concerned now about helping her get her slime coat and her strength back. She's eating a little, but not her usual.