02 protege5 abs problem?

i have a 2002 mazda protege5. my abs light as well as my brake light is on (on the dash) i have taken it to a couple different places to get it looked at and they just act like it isn'tot a big deal. i have a few problems with my brakes right now.. the front left wheel starts clicking when going down the road. and sometimes my back right tire starts squeakingng when i drive it for awhile, but not all the time. does anyone know whats going on. i have replaced both rear calipers just a few months back.