Why doesn't Alipay send a text message to the bank for a refund?

After the refund on Taobao, Alipay showed that the money was returned, but the bank did not send a message to the mobile phone. There are many reasons, such as the following:

I. Expiration of service

Many bank SMS services are charged. If the service expires, you can't get a short one without knowing it.

Second, the signal is not strong

It is also possible that the cell phone signal in a certain location is not good and it was not received in time, which led to the delay of the short message.