Zinks

Hello, sorry for the inconvenience! I was trying to evolve my Nidoran M, but as soon as it was about to level up to lvl 16 I received a phone call and the evolution ( y or no ) choice didnt pop up I thought leveling it to lvl 17 will fix it, but it didn't... Is it possible to delevel back to lvl 15 so I can evolve it? Server : Silver In-game name : Zienks Pokemon ID : 38698037 Thanks.