Hi @Hongchao , here you can find the possibilities to cancel a subscription.  (Use Google translate). 

The easiest way for you would be to do this online via your my-tmobile portal.

Thank you Eric! I’m not in the Netherlands right now and I can’t get the online cancellation form. Could you help me with this?

No, i can not. I am just another customer.  But the online settings can be accessed from all over the world. Otherwise, make sure you have filled in the details in your forum profile. Than a moderator can take a look next week.

Hi @Hongchao 

I can help you with your request. Is your contract term over or would you like to buy off your contract? If you can send me a private message with your 06-number, name, birth-date, address and the last 4 numbers of your IBAN i will be able to check if I can file a cancellation request for you. Please keep in mind there is a one month cancellation period which means your contract will be terminated a month later. 

Looking forward to your message!