What is the company?
It would also be helpful to other people looking for a web host to see who this host is and to stay away. It also might open up more issues from other users who can relate who used her.
threatens to fight any chargebacks
She will never win as long as you did not sign a sales draft or something similar. Let her fight the chargeback's. It waste her time and also lets her merchant bank see the way she runs her business.
Also, as I am sure you can see from others who had similar issues on these boards, write the BBB, FTC and AG office in her area. If you do not let them know, they can not help. Get the other 100 people who complained to do the same.