Quick fix....I had this problem too drove me crazy for a week. it is from setting up a web based email like hotmail or yahoo on your verizon wireless pda. all you have to do is highlight the email account go to account settings and uncheck "keep my inbox up to date". when you check your email u will have to refresh but at least the texts stopped. it worked for me... I finally got a verizon wireless operator that knew how to help me.
I am bombarded with OZMail text messages soon after I activated my phone. Each text message costs me money. A call to OZMail offices in Canada was useless due the attitude of office people. Sent 'STOP' reply as noted in each text without any success. Extremely annoying and costly. Need to stop immediately.
I have a Blackberry World Edition.
here is a link for verizon, I hope it works. step by step to set up firewall.
!http://search.vzw.com/?do=viewdoc&id=16209&p=3015&supportview=1
Verizon can stop this by blocking all sms text messages. so if you love texting, it won't be a good soulution for you. Just call them, they will do it over the phone.