Who called from 3019909338

Called on my cell phone and hung up when I answered.

Called on my phone and hung up too.  When I called back, it was busy first time and rang second time nobody picked up.

I've gotten 2 calls from them tonight.

The person did call back.  Spoke in British Accent.  He stated that he is calling from SmartOne who supplies gas to Washington Gas and because gas is being used for home heating they want to give 10% discount for two months.  

I stated that I want something written and person raised his voice, he said there is no papers to sign, I will just get discount from Washington Gas and letter from them.  

As soon as I said that my Dad is the account holder, he abruptly said "thank you for your time" and hung up.

continues to call my number.  When I return the call the line is busy.