When I was a student, someone sold China Merchants Bank credit cards in the dormitory, so I made one, but I never gave it to him, and I submitted a copy of my ID card myself.
1. When did he sell it to you? If it is this year, it must be a liar, because the student credit card of China Merchants Bank has been blocked this year.
2. If it was before, don't worry. You should call China Merchants Bank to ask first. It is also possible that your address can't deliver the letter. Under normal circumstances, they will still handle it!
I hope my answer can help you.