I just wondering , how can this type of mistake possible? I think fee are automatically being charged right. This is such huge huge mistake ever , I can't even imagine if that was me. Pheww. Looking at current btc price and 15 btc as fee. I'm going to shop and buy myself a rope. LoL !
The fee is whatever is left from the inputs that is not spent. If you are using some a wallet this shouldn't happen unless there is a bug.