Fnb bank attorneys threatened to take all money in my business account

I run Supply and deliver Small business in East London. I was approved for a overdraft of 25k due to good business then in 2022 if Iam correct. Last year business was not good.Fnb froze the account due to non paymentof the monthly fees for overdraft. Then we could discuss and sort it out as monies were coming in there and then.Now on 5 months late on arrears. Monies went to the account and they closed it.Problem that is moneyI had loaned to do a job.Fnb can't take it all .Rather they take the arrears of 5k other than taking of the whole of 22k as this is borrowed money so that i can have business and pay my debts.the account is closed and more monies are expected to enter there