I get calls from this company, every two days, when you call back, no answer. Cowards, they don't let you know who they are.

I have been getting calls from this number on my cell phone!  And I am irritated.  Don't know who or what company it is from!!!!

Go register your number with the Do Not Call Registry
https://www.donotcall.gov/
If you call them back and get anybody in person to answer, tell them your on the Do Not Call Registry and that if they don't stop calling, You will file a compliant with the Do Not Call Registry.
The Do Not Call Registry. will notify them with a warning and monitor any calls to to the complainants number from the callers numbers they will find themselves in deep [***].
You must register before you can file any complaints and it can take up to a couple week before your number is enable with the registry and you must re register your number every 5 years.

Virgin Mobile service has a section in the phone, Apps, and more section on their web site that allows you to block callers if you have Virgin Mobile service.

Any time you get calls you don't recognize and it's from a solicitor they will never let the call ring your phone over 2 1/2 to 3 ties because they don't want their recorded message machine to be tied up with voice message calls.
Do not answer any colls that only ring 3 or less times.

Actually you need to renew your registration every six months.