does not find interest rate

some key functions show error messages. no support. it costs $20. I am ripped off my money. now I have to buy another. what is the point? this is the equivalent of stealing..... I think all positive reviews are fake. the calculator cannot perform simple operations such as find I when PV, FV and N are given. As well it does not find N. DISAPPOINTING.

opinonated consumer about Calculator12 RPN