Synonyms for Lambast:

n.

condemn, bash, pillory, decry, denounce, bring/call/hold someone to account, cry foul, jab, slate. lambast (noun)
rag, reprimand, berate, flog, chide, jaw, lecture, scold, trounce, reproof, chew out, lambaste, chew up, dress down, rebuke, cane, remonstrate, bawl out, have words.

Other synonyms:

decry, denounce, pillory. bash, condemn. jab. slate. Other relevant words:
jab, condemn, denounce, bash, pillory, slate, decry.