Look at the numbers you have blocked and the numbers you need to call. After examining both, try blocking entire area codes (where possible) instead of individual numbers. This will also work for toll free numbers. You'll gain some space that way.
Caller asked one question "Did you vote in the last election?" Answered No because I suspect it is a variation of the "Can you hear me" scam call where all they need you to say is Yes. Suddenly the one question became two, to which I also said No. Then more questions all geared to elicit a Yes response, I kept saying No. Finally they asked if they could call back once a month, I said No. They then asked me to spell my first name, which I spelled "N O"