Walmart Family Mobile Crooks,Thieves,Liars,Misrepesatative Internet

Someone gave my son an iphone 3g that didnt have service,so we went to walmart to get an at&t simcard. The employee recommended that we try Walmart family mobile because it was cheaper and would work with the phone. She told us to bring it back if it didnt and we would receive a complete refund. ......It did not work. When we got home and activated the card they told us to put it in the phone and it would take 2 to 48 hours to receive an activation message.We never got the message and retruned the card to walmart. I called and deactivated the card like she told me to and now im receiving a bill for $8.80. Im not sure what for,but maybe its for trying their company.I have written them a dispute,called every number I can get,I even sent walmart.com and email that has never been responded to. But still,they say its going to collections now. I called another number that I got from walmart.com and spoke with someone who admits that my bill shows that there was never any usage  but she cannot take it off.She told me that I could pay it by phone for free. I hung up with her to calm down once again and decided I would pay just so it would not go onto my credit report. I called back to pay and the man that answered now says that I have to pay another $5 to pay my bill.Walmart has joined the hood-marts. How dare they treat their customer with such disrespect! Now Im up to paying $13.80 for services never rendered! No wonder they wont give you the number for customer disputes. Isnt it ironic that a cell phone company dont have a phone number,they can only be contacted by email or mail.Something has to be done about this Sam Walton!