Prank phone calling software & texting software

The software Im looking for is one that will make repeated calls with random numbers and send multiple text messages from random numbers. I am trying to prank one of my friends and need this, also I need it to use random numbers because I dont want them to be able to simply block the phone number that is calling. Think of it as a phone bom-B-er. Windows based program, I know it exist I just dont know what its called.