Trust people?

I want to get your views about trust? Is it of any worth to trsut people when people have deceived you. Alright........... Let me narrow down my question. If any person (may be a close friend or loved one) does not fulfil his commitments and dishearts us time and again but he wants otherwise from us then should we trust him and continue the relationship or go further leaving him behind without caring about his feelings as he does not?????????????????