So you have about 35k in your account - I'm assuming you didn't trade it off on Betfair or another exchange, and unless you were backing an odds on favourite, I can't see any reason for complaining to be honest. Either leave it in there for another 4 bets or take the 3% fee. You clearly have enough cash behind you to be placing large wagers and unless like I said, you backed an odds on favourite, you should be in profit regardless of the fee.