Betting companies don't usually worry about bets placed using debit/credit cards, or directly from bank accounts,simply because any winnings are credited to the relevant accounts. i.e. there shouldn't be any way of the thief/fraudster getting hold of the winnings.
There was one well-reported case where a guy stole a woman's debit card and used it to place a long-odds bet with a High Street bookie. When he went to claim 'his' winnings (nearly three hundred pounds) he was told that the money had been credited to 'his' bank account. When he then kicked up a fuss and tried to demand cash, the police were called and he got nicked. (The betting company allowed the woman to retain the winnings from the bet).
So I can't see how the fraudster hoped to gain from placing bets with your money.
Professional gamblers often place bets totalling hundreds of thousands of pounds in a single day, so 80 smallish bets aren't necessarily going to start alarm bells ringing with a bookmaker.
To be a bit pedantic here, I suspect that, rather than your bank account being directly hacked, your debit card has been cloned. That would explain why the bets were all for £29 (just below the £30 maximum for using the contactless facility on the card).