heres some info I recieved via email which may be the answer and hopefully the solution to your spamming:
all cell phone numbers are being released to telemarketing companies and you will start to receive sale calls. YOU WILL BE CHARGED FOR THESE CALLS....
To prevent this, call the following number from your cell phone:
1-888-382-1222.
It is the National DO NOT CALL list.
It blocks your number for five (5) years.
Hope it helps!!