Can I refuse the legal letter from Weizhong Bank?

No, the lawyer's letter is a very serious or even a serious warning. If the parties ignore it after receiving it, they will face litigation. If you don't want to be sued, you should consult the bank privately before being sued after receiving the lawyer's letter. If you ignore the lawyer's letter after receiving it, or the negotiation is still unsuccessful, the bank will take further action and bring a lawsuit directly to the court.