So a professional checked the seats? Right?
It would be very unusual to have to replace the valves and not need the seats cut at the same time. If the valve faces wear they put uneven loads on the seats and cause dimples and ridges in them that have to be cut to remove so the new valves will seat correctly. If the seats are not cut when needed, the new valves will not seal correctly and thus will not last. If the seats are too worn they would need to be replaced.
This is just not a step that needs to be overlooked to have a good job done.
Of course it your dime, so either do it right the first time or expect to do it over again shortly. You call!