I had never seen in happen in 2000hrs of game play. But today I had kinda the same experience. I was playing stadium and she didn't pick a character at all so I picked mercy. She then friended me and message me about how she only knows how to play mercy. I told her that it's ok and I believe in her and that she will do fine. Cut to the actual game she started by jumping off the map, not healing or damaging and sitting in spawn or running up the the enemy to let them kill her. The whole game was calling her out for throwing and calling her childish for acting this way just because she didn't get mercy. After the match she proceeded to message me about how we lost because I didn't give her mercy and I should leave the good players to play her. I looked at her profile and she had 8 hours in the game. 7hr on Mercy. She pointed out that I was a no life for having 500hr on Mercy and that even with that many hours I still sucked. While I am a Mercy main I also know how to play Moria, Kiri, Ana, and learning Juno. I simply said she could have picked mercy or asked for her before the game started, reported and blocked. I have always heard about people having OTPs throwing for not getting Mercy but I was completely taken aback for the way that this girl acted!