Brakes? Hydraulic pump failure

I have 1998 Toyota 4Runner 6 cylinder and i just recently
had the brakes done but aftet a week or two it felt like it
wasnt stopping all the way again. It seems to get worse
and worse each day.. I backed into a pole because the
brales failed, i was backing up about to pit it in drive and
the brakes completely let go.. Another time i was coming to
a stop from a residential onto a busy main street as i was
easing up to the stop sign and hit the last brake it didnt
stop at all i pressed the brake multiple times and it didnt
work i was blessed i made it through that intersection alive
. so what could it be im hearing maybe my hydraulic pump
or master cylinder? Since its not the brake pads.