Fluffytime

So, somebody wanted to trade their haunter for evolution. They asked me, so i helped them. However, im in johto right now and I can't put the haunter in my party to retrade it back to him. I posted a picture of the reason as well as his user and mine. Please help me give it back to him. I feel so bad now. ;w;

I recently caught a gyrados and the pokemon disappeared from my party and wasn't in the pc either. I wasted on close to 10 pokeballs and 4 greatballs on it lol