Who called from 3478176066

Pick up and no responce.

Called several times, I didn't pick up.

That number called me and said they were from atnt they asked me for my social security nymber. Be really careful at them

I got a call twice everyday from this number I never answer....

I have been getting a call ever since AT & T directed me to this number for a promotional and the person was seeming fishier by the moment so I ended up not taking the $100 dining out card from them... the number is coming up as +34 which seems like it is from Spain. How can I stop them from calling without answering the call?