I doubt many people will know much about the wipc wallet here (hands-on I mean). If you’re sure that you are typing the correct passphrase, you should probably to contact whatever customer support the wallet provides, or any of its social media channels.  There’s a (pretty inactive) WipCoin Ann thread here ([ANN] Official WIPCOIN (WIPC) POW | MASTERNODE | INVESTMENT - x16r). If that’s where you downloaded the wallet from, then try getting some assistance through them.