How to refuse others credit, civilized language

There is nothing to be ashamed of when you ask for money in business.

If you dare not ask for money, then don't do business.

You don't need to consider any reason. If you don't have much money, you can say that if you don't have money, this thing came from me.

If it's a business, it must be, first-hand money and first-hand goods, because I don't have the money to get the goods, people won't give it to me.

Or you can put a reminder card at the cashier, as shown below:

Small business, small profit, no credit, please cooperate, welcome to visit again.