This number keeps calling but when I answer there is either dead silence or music playing...nothing else so far.  Really wish they would stop.

I received a few calls from this number.  The caller never left a message.  I dialed the number and when prompted to enter in my account number I entered  "0" and "#" and was transferred to an operator.  I quickly explained I did not have an account number and they looked up account info through my phone number.  It appears Medco administers pharmacy benefits for Western Health Advantage.  I asked them to remove me from their call list.  They apologized for previous callers not leaving message, and agreed to remove my number from call list.  Hopefully I won't receive any calls from them in the future.  

p.s. Going to contact WHA about the frequent calls.

Received a call no response, then when calling back they ask me for personal information for discounts on prescriptions.

This company will sell any and all information you give to it that they get from you after promising to sell you your perscriptions at rock bottom prices.  And how do they already have your prescription knowledge?  Good question.

thanks to Sarah. I will call Medco tomorrow and, "get nasty with them." I've had enough.