Free caller ID

I dialed this number by mistake as I tried to contact Frontier phone company which correct last four numbers are 8101. This wrong number ending 1801 got connected and the computer answered saying this number has been switched and the new number was 80071XXXX. So I dialed that and another computer answered and asked me to verify myself by speaking my last name and spelling the first 3 letters, My first name, And city. The answering robot then went into search for my telephone number following by