Why am I €147 in the red?

I didn’t do anything. I only have the account for credits. Not debits

If there’s only money on it, you can’t have a minus.

I didn’t give any debits to the account. I just get my salary from the mini job on it. I’ve only been debiting the account to my account for months. That’s always 200€ and more isn’t going down.

Can it be that has been left out of credit or is it less?

If you left 200 rebooks every month but in a month only 53 on it, the rebooking would go to the minus.

This is the fact that any credit and debit (print, permanent order, proof of…) can be traced to the account statements or online banking.

If you don’t have the necessary access, for example, because account statements are lost, you can also ask the bank. But money cannot appear or disappear without proof on the account. So you should be able to see what went down and went on.