How much does it cost to change a 3G card into a 4G card? How to deal with it?

1 and 3G cards are exchanged for 4G cards without charge.

2. The treatment method is as follows (taking telecommunications as an example):

① You can edit the short message "28 1" and send it to China Telecom's short message platform to make an appointment to upgrade 3G to 4G card replacement service. The short message of China Telecom's short message platform is as follows: You have successfully made an appointment to replace the 4G card for free. Please prepare a copy of your ID card to keep the communication open. Customer service staff will contact you within 2 working days;

② Log in to Huan go, select "3G to 4G" in the special area, select the most appropriate upgrade path button, and click Upgrade 4G (please provide real and valid identity information to ensure successful handling and delivery).