Rosie answers calls in English and Spanish and is banded on minutes rather than metered. If a month runs past the plan allowance it moves the account up to the next plan at that plan's standard price, in its own words: "No per-minute overage surprises, no service interruptions, no missed calls." That behaviour is published twice, in its pricing FAQ and again in its terms.
What the entry plan cannot do matters more than usual here. Warm and live transfers, and appointment booking, both need the middle plan, and Rosie has no human backup of its own, so a caller on the entry plan reaches no person at all. Above the top published band the vendor asks you to get in touch rather than publishing a price.