How would you handle this B*TCH?

My family say i should ignore this because it shows how pathetic my friend is.They started laughing and they said 'wow she's a joke.' But i dont find it funny. Me and my bestfriend were supposed to attend my other friends do...lets call her viv. We cancelled because i was sick and my bestfriend didn't want to go to vivs do because viv was such a *****. She didn't want to go on her own to vivs because she remembered all the mean stuff viv had done in the past. She put us down when there's other people around, whenever we achieved anything she made us feel small, if we ever got male attention and she wasn't she'd either be real mean and bitchy,or she'd shove her face infront of the guy and try and steal him away. She was always jealous about how close we were. If you ever confront her about any of these things, she starts crying and telling you that youre really insecure or she wished you didn't feel so threatened by her. Anyway i was really sick, my friend just texted her pretending to be sick. I called viv twice to make sure that she was okay and to confirm that i was genuinely sick because i'd practically lost my voice. Later on i get a prank call from who i believe was her boyfriend.It was an Asian guy, 'she's told us that he's an asian guy.' He knew my nickname, which only people in my close circle know my nick name, when i give out my business cards i usually tell people my full name, he said he met me in places i know he'd never met me in because i don't go to those areas, my bestfriend said Viv knows people in those areas. He didn't swear at me or anything, but i'm just pissed off. Me and my best friend have tried to support Viv so much, i've tried to bring them closer together, because her and Viv used to be really close, we've listened to Viv and supported her when she was being bullied or picked on by people. People dont usually like Viv she comes across as cold and unfriendly, when we used to be near her people that we were close to would avoid her, my family never liked her. Secretly i was jealous of her success, but i still tried to support her, when i achieved anything she always put it down or would be patronising. Do i just ignore the prank call, and laugh at her like everyone else did, or do i react...what do i do?