Who called from 8134356136

Received approx a dozen calls from 813-435-6136.  Answered once and they did not respond, tried to call back and the number was not a "real" phone number.

It's called about a dozen times and no one is on the other end when I pick up

I get called by this number at least 5-6 times a day and its been going on for about a week now.they hang up when i answer and i cant call back because it sounds like its disconnected.

Also get multiple calls daily / hourly from this number who never answers or leaves messages.

Have been getting calls From this number 4 weeks. tried to call back its not a working number. how to block a non working number?? drives me nuts!!