if you refund your ticket at the ticket window, you must keep the receipt after the refund. when there is any problem with the refund, you should write down the information such as the date of purchase, the date of refund, the number of trains and the amount in time, so as not to forget it after waiting for a long time. Let me introduce some experience here. If you buy tickets with a bank card, you should bring your bank card in addition to your ID card when you change the ticket at the ticket window, and make sure that there is enough money in the card to buy the changed train ticket. In fact, it is equivalent to buying a new train ticket first and then returning the old train ticket, but there will be no refund fee for changing the ticket.
generally, the refund will arrive within a few minutes after the successful refund of online banking, and the credit card may be a little slower sometimes, but it will arrive within two or three days. If it takes more than 3 days, it is likely that the refund is abnormal, and it is very rare to return it automatically for half a month or even more. At this point, there is no way but to wait patiently. Because the answer given by calling the railway customer service is the same, and their attitude is not very good, why waste your phone bill. They will not handle it for you within 15 working days.