Is it stupid for a cell phone company to require you to have a landline phone to handle certain transactions?

I have had a tracfone for a few years now. It was my first non-traditional service, and when I activated it I also happened to have a landline. After having the tracfone for a few months I decided I did not have to waste money on a landline phone and got rid of it. I recently upgraded to a much better phone for just $29, and tried to have my number and minutes switched over. Well, it took me 8 phone calls, including one from a landline I had to drive 12 miles one way to use, 2 nasty e-mails, and needed a supervisor to get involved.

Phone finally works, but the minutes never followed. I just wasted 30+ minutes today trying to find out why, and they tell me I need a landline phone to handle this. Now why would a cell phone company say you need a landline phone? Should they not have a system in place that allows business to be transacted on their own phone? Does anyone know if this is true of all the pay as you go, no contract phones?