How to complain if the third needle is hit by someone else under an assumed name?

You can try complaining on the 12315 platform, which should also help. Maybe you can also try the black cat complaint platform. Of course, I don't recommend that you spend too much time on the black cat platform, because the ugly point is that you spend money without doing anything, and the speed and efficiency are very slow.

Maybe you really can't help it. You can also ask the local police for help. There must be a way to help you.

but you can also continue to vaccinate, which should be ok.

Ask vaccination clinics and community workers to clarify the situation. There is a phone number at the vaccination site, and your ID card can be used falsely. The phone number is definitely different from yours. After verification, you can get the COVID-19 vaccine.