Debt collectors can go into your bank account but only with a court order after the debt collector takes you to court and sues you for the debt.
The debt collector has to sue you and win a judgement against you for the debt.
Then if the judge gives the debt collector permission to take money from your bank account to pay the debt then they can do so.
However you can always remove the money from the bank account and then open a different bank account and then the debt collector cannot take any money from that new bank account without a new court order.
Debt collectors can also garnish your wages when they win a wage garnishment judgement against you.
If you are being sued for a debt you need to show up in court or the judge will automatically favor the debt collector and the debt collector will automatically win the judgement against you.