Do i give up or?

Hi! First time posting on this thread, but i need some advice. So I've had this friend for half of my life, and she and her parents moved and kinda fell of the earth. It's been about 8-9 years since I've heard anything, and today an old picture of us popped up and i got curious. So i looked up her name and no social media of hers popped up. But there was a number listed for her dad. So i called dad bc i haven't heard anything and it's been years. Since they just dropped of the face of the earth. He sounded like he didn't even know who I was and i explained it to him. He kinda seemed standoffish. He said he would pass on the message but i doubt that. I kinda regret trying. I just miss her so much and i just wanna atleast know what i did wrong. Like why did the person i grew up just drop me. We were kids so it wasn't her choice but idk. Do I keep on trying?