Text Message Charges from Solomobile

I purchased a plan with solomobile and since activation i have been getting these "short code program" text messages which charges anywhere from $2 to $5 per incoming text. After speaking to the solomobile both at the kiosk where I purchased the phone and also calling their technical support, solomobile says it's a 3rd party text and they just past the bill to the consumer. Since I did not subscribe to this I end up paying for this. 1st month was $21, now it's $42. I can't get them to reverse the charges and I'm not sure where these messages come from. How does a consumer protect myself from this?

Victor