My dilemma now comes in where Company B is desperately trying to get me back and is offering me a lot more money with more of a managerial position. I told them that I can't just leave, as that would be job hopping and is unfair to the company I just joined. Their response was that loyalty is for dogs. They have told me things have changed and said they made a mistake letting me go.
Sounds like an ex wanting you back.
I don't think company B has changed at all personally.