Yes it's a scam DTE would already have your account number and the caller ask you for it. THIS IS A SCAM TO STEAL YOUR IDENTITY. IT'S A MICHIGAN NUMBER.

caller from this number call and hang up

Got same call, not exactly a scam as much as it is an gas company trying to get you to switch to their company, making you think their dte so they can get your accounts number and change you without your knowledge,  i told him the facts and he begged me to swich or he would lose his job, i told him where to go without anyway of getting back.

Called my mobile. Nobody there so I hung up.

We'd all be in the soup kitchen if we accepted every dubious offer just to keep illegal cold callers employed.