Are you sure they are still offering that feature? If it's an "import" (your private keys got transferred to the site) and not a "sweep" (your funds got sent to one of your blockchain's addresses), the bitcoins should still be in your paper wallet. If that's the case, you could use one of these solutions:
1. After installing Electrum, you could go to Wallet => private keys => Sweep:
Your funds will be sent to one of your electrum addresses.
2. Or using Coinomi (a mobile wallet, not suggested as Its not open source). Just go to your bitcoin wallet and click the
scan QR button on the top right.