I have never lost any wallet with btc so far. Web wallets are totally OK for small amounts and when you have a backup or a you export your private keys. The only btc I lost was in Bitfinex hack and i do regret keeping funds in an exchange for long time
Good thing that my exchange site is still not failing me. And I am not even losing any amount with my bitcoin wallet.
Since I am letting my bitcoins grow to their site still I am believing that they will have good security if there is a breached happened.
I will just ask them for a refund, if possible.