Hello Jasperyuan,
Welcome to the community!
Sorry to hear you are currently unable to activate your new SIM card. The requirement to receive the verification text to your old SIM card is to prevent SIM-swap fraud (see also here etc). Since you no longer have your old SIM card for the verification, you will likely need to go to a store with adequate identification in order to activate the new SIM card.
You should note the forums are community-driven and not intended as a venue for customer services. We do not have access to customers' accounts nor would we be any position to assist you with activating your new SIM. If you would like to discuss your matter, you would need to contact customer service. In addition, they can also be contacted via Live Chat, Facebook, or Twitter. Those methods can be accessed via the contact page posted above. Though, you would likely still need to go to a store to verify your identity.
Hope this helps 😀
Cheers
