I used to be a contractor and was sometimes bad at processing timesheets and invoices.

I had one occasion where I had (numbers made up because it was ages ago) £100 in the business bank account with no overdraft facility when a £150 payment went out.

The payment went out putting me overdrawn. They waited a day before deciding that I wasn’t allowed an overdraft and putting the money back.

During that 24 hour period a payment for £25 was processed and blocked because I was overdrawn.

They then charged me two fees for refusing the payments even though I had money for the second one in the bank.

I switched banks right after that.