Contact?

I know it’s been a while since I last wrote. Things had gotten hectic over the summer and with back to school. Now that things have calmed down, I’ve been thinking a lot about contacting my half-siblings via my birth father. He hasn’t responded to any of my attempts to reach out to him, but I feel like I gave him many chances. Just because he doesn’t want to know me, does that mean he gets to make the decision for my siblings? I don’t even know how many kids he has, I just know he has more than 1 and 1 is a sister. Apparently we resembled each other quite s bit as little girls per my aunt (who won “guess the birth father”). He has no right to decide who I know or whether they know he isn’t perfect. I did nothing wrong. I feel like all of my “parents” have made (poor) decisions for me my whole life and I’m ready to make my own. I’ve found the one sister on Facebook, so am now just trying to think about what to say. Not quite sure how to say, “your dad isn’t who you think he is and by the way, I’m your sister.” Maybe not the right tactic. Maybe I just say, “I”m your sister. Your dad doesn’t want to know me, but I’m hoping you do.”