No answer on other side when I pick up

it is the third time calling in two days..since it's unknown i let it go to voicemail..but no message..why call someone so many times if you have nothing to say or message to leave..really weird...

This can happen when there are more phones dialing out then telemarketers to deal with the calls or when someone picks up before you do.  Consider getting a call blocking device or phone.. You can google them and many are around $40.00 or so. If its a cell phone, some already have call blocking, if not, there are free apps on the web that will work for some. You can google this. If you have a smart phone, there is a free app called call control. Iphones appear to have apps also. Another one is called Mr. Number. For tracfone & straight talk:
https://play.google.com/store/apps/details?id ... .tracfone&hl=en

http://extras.straighttalk.com/en

http://www.youmail.com/home/carriers/straight-talk/block-number

https://www.straighttalkwirelessforum.com/viewtopic.php?f=6803&t=55006

Report your callers here, not just to the DNC alone:

https://www.ftccomplaintassistant.gov/#&panel1-1
https://esupport.fcc.gov/ccmsforms/form1088.action
https://complaints.donotcall.gov/complaint/complaintcheck.aspx?panel=2

For text messages: forwarding any text message spam you get to the short code  “7726,” which spells “spam” on most phones, to alert your network operator to the abuse. ATT won't accept 7726 But they will accept BLOCK and return a message that the web site is blocked. forward the texts to 7726 or BLOCK, depending on your phone carrier.

By State DNC lists:
http://800notes.com/res/DoNotCall.aspx

FCC Abandoned Calls Complaint form:
http://www.fcc.gov/cgb/consumerfacts/1088D-R.pdf
email:  fccinfo@fcc.gov

To file complaints on Foreign company's:
eConsumer.gov: Report Your Complaint
E-mail: econsumerwb@ftc.gov

Received 2 calls in 3 hours leaves no message

I get 3 or more calls everyday at all different hours, no messages are left or no one answered when i pick up the phone.