The online merchant bank did not have a loan, but received a text message asking for repayment?

You can call customer service to ask, sometimes there are many fraudulent text messages. At the end of the year, swindlers come out to cheat money, so be careful.

But I don't think the amount is very large. Will it be an annual fee or a card fee? If so, you'd better pay it back and then cancel some business that costs money. If not, that's best.