They required documentation (for example, the credit card statements), so a call wasn't enough, I could mail or fax. But I did call them multiple times when trying to resolve, which was also a hassle. It's absurd that fax was the only means of electronic communication acceptable. How can you not accept email or have a web application? I don't know of a single other state that requires electronic communication solely by fax. I took it as a sign that CA wanted to create artificial hurdles so we would just give up and pay, which is ultimately what we did.