These are called one ring scams. When you call them back they install malware on your phone. You need to report this & block numbers. If you have already called them back, you need to chech your bill CAREFULLY & have your carrier remove any cram charges
This company calls me at least twice a month, shortly followed by another phone number, which I can only assume is from the same company. (336)728-1609. I have never answered, because they call me while I am in class and am unable to answer, and they never leave a voicemail.