Why does Verizon say their unlimited data plan is $29.99/mo but charge over $60?

So, I got a phone (palm pre) from Verizon and a data plan. According to the research I had done, the unlimited data plan (which I got) is $29.99 per month. I’ve gone two months now and the first month’s charge for “pda/smartphone unl” was $44.99. The second month’s was north of $60. I haven’t bought any non-free apps (palm doesn’t have very many good apps as it is). What gives?

PS – fuck you Verizon – someone needs to read John Rawls’ “A Theory of Justice”