I sometimes make a mistake too, in which case I just use the cashout function to cancel the bet. Actually happened just yesterday (somehow I clicked on Turbobet or whatever option it was and it places bets as you make picks. You lose 4-5% with cashout, but you'll make it back when you score a winning ticket, right?

Yea, exactly how it happened. When i made the mistake, I had to cashout, what I got was $9 out of $10 I used in staking, I had to recover full amount by betting again, I divided what was left, staked one si,de which i lost then doubled the odds and won back full amount which enable me register in the marathon.