magicJack Refusal to list rates for pre-paid calls West Palm Beach Florida

MagicJack refuses to disclose the details behind this statement: "We may require prepaid purchase and/or we may charge you for calls to conference lines, platforms and certain non-ILEC area calls, or any call wherein we incur a cost from another carrier."

After years of using MagicJack, I've suddenly begun getting a recorded message when trying to phone certain numbers (USA domestic). The message tells me I must now purchase pre-paid minutes to reach these numbers (apparently served by certain phone providers MagicJack isn't friendly with).

There is no information on the MagicJack website about who those providers are or about the rates charged, which presumably vary. MagicJack online help chat (the only help ever offered) refuses to state rates.

Does MagicJack really expect its customers to buy and spend "pre-paid minutes" without knowing prices? I sure won't.