Called my cell phone, but couldn't hear anything.

It's Santander USA, if you recently purchased a car, or inquired about an auto loan...

called my cell - no message left

They called my cell, then hung up without speaking.  I called back from another phone - it's Santander USA.  They service my car loan.  This is the 3rd time this company has called and hung up for no reason, and I purchased my car less than 2 weeks ago.  First payment isn't due for another month, so it's not collections.

Last time I returned the call, I was told they were "probably just verifying the validity of the number".

Same here... called and said nothing, then I heard a beep after my second hello, and they hung up.  I just purchased a vehicle with them too, so that must be who it is.