Immature people

So I have this person in my life who thinks its okay to talk down on a family member of mine, for all to see. I got offended and went to this person about it and they just brushed me off like it was nothing. Im sorry but I will forever defend my family members when it is needed. They say that they get along really well with my family member but yet they bash them when they cant defend themselves? I dont think so!! Anyway, I just had to vent for a minute so there ya go.