I noticed that many people have complained about the number 1-800-266-9420. I also get calls daily from this number and it only rings for a second, and I call it back and get a busy signal. I really wish I knew what this was and I want it to stop

I get calls from this number 800 266-9420 several times a day. Nobody is there and if you call back it goes to nothing. I am sick of these calls. I am on the national do not call list and i am still getting them.