回複：綠卡上的A number是2xxxxxxxx,這是個新number, 而以前收據上的是0xxxxxxxxx. 謝謝！

An A number should never be changed once you received one, just like a SSN. You need to contact USCIS customer service with the issue. They will tell you how to get it corrected. Or consult a lawyer if you have one. Good Luck!