same thing, got a call from some student loan service, asked to speak to a manager and was hung up on.  Call backs to this number claim not in service.  methinks its a scam.

Never answer these calls, your phone is hackable just like a laptop
if you answer the call you just opened the back door to your phone.
(It's why there is no one there when you answer)
Same as you should never open a unknown Email.. and don't ever call
these numbers back.. once they get in your phone they can get in
your home wifi...DON'T EVER ANSWER UNKNOWN PHONE NUMBERS is sucks
but that is the facts of the technology we use every day..If it's important
the person will leave you a message.. You can get free phone number
blockers form google play or other app stores.

Calls 5-6 times a day. Most times nobody answers when I say hello and the other times they ask for me and then hang up. Tried calling back to have my number removed from their dialer but I receive a message that says number is not in service. Annoying!

Calls 5-6 times a day even around 11pm.

stop calling me