Who calls from 866-605-4528/ 8666054528 ?

I keep getting a call from 866-605-4528 and they state they are my service provider and want to go over my service plan to make sure I am happy with the plan I have or maybe there is another plan that would better fit my needs. I just googled 8666054528 and it appears that many people have gotten a call from that number and it may be fraud.

So who calls from 866-605-4528? I don’t think it is Sprint. Sprint normally sends a text message or an automated message, this was a human being.

-TaWana