Why can't Tencent Micro Card be bound again after it is unbound?

Tencent micro-card unbinding can't be changed when binding the mobile phone number that may be unbinding, but the micro-card can be bound with the new mobile phone number.

re-bind the personal account in the micro-card program, and log in with the new mobile phone number registration verification code.

you can apply to the administrator for rebinding at the micro-card program end.