Called my number, and left a 33 second voicemail.

Voicemail said this call was related to savings on power and gas bill, and that claiming it would require me to text "POWER" to a shortcode, which sounds like it would've made me subscribe to something, causing me to pay.

Got a call from 6072035673 when I answered they hung up.

I got the same thing – they wanted me to text "POWER" to them to get a discount on something.

Same here, just got the automated telemarketing call about texting to get a discount on power (electricity, I presume). No opt-out option was offered. Not impressed at all, I'll be reporting this number to the Do Not Call list. By the way, the caller ID name is "NY Service".