[2.0] Voice Calls through GSM mobile

Hi,
I want call (call to landline or mobile) my list of customers through GSM-bluetooth technology. I stored audio files like .wav or .mp3 etc. How can I call the customers automatically and play the audio files to them. If I should buy any extra equipements please inform me.

Current I am having

Environment : Windows XP/Windows Vista
Stdio Version: Visual Stdio 2005
Language : C#.net
Bluetooth Mobiles : Nokia 6021,Nokia 6085 and Motorola L2
Dongles : Gigabyte,Zippys,X-Micro,IO-Gear
Framework version: DotNet 2.0/DotNet 3.0 and 3.5
Drivers for Bluetooth : BlueSoleil,WiddCom.