Facing problem in changing address online and getting card vitale

Hello, I'm an international student. I have received my social security number but now its been more than 6 months I didn't receive form for my card vitale also not able to make account in ameli online. It's showing me error. Even not able to change my address. kindly guide me with this procedure. I went to office to ask for my problem no one helped me they just told me to call helpline number and no one picked call. Kindly help me in sorting out this problem. I'm struggling from so long.