Why do people who claim to be law firms help a bank to say that they are entrusted to sue, but they say that they will not sue? Why do they always call with virtual numbers?

Some are true, some are false. If you really owe a bank loan or credit card, the bank will entrust a collection agency to collect it, and will also entrust some law firms to send lawyers' letters. But it is impossible to sue some customers who owe a large amount of money just because one person sues hundreds or thousands. The other party calls you only to urge you to repay the loan. If it is not returned for a long time, the bank has the right to bring a lawsuit to solve it.