Walmart billed me for phone service which has been cancelled Comstock Park, Michigan

on Dec 2012 i purchased 2 phone with advise from T-mobile rep on site in walmart also signed up for the family plan. 2 days later i was on the road to Virginia making a delivery ( I'm a over the road truck driver ) i had explain how straight had some states where the signal was too low to make calls , was told T-mobile was better more signal towers. After making my delivery the phone would not work tried everything including turning the phone off trying to reset it. Needing to get in touch with my company to report and get dispatched from Va. i used a pay phone. Upon returning to Grand Rapids i went to Walmart ( phone still inop) told the service person at the phone center , i was advised i could keep the phone(s) or turn them in that day and the Family plan would be cancelled . purchase 2 phones again and went with the straight talk plan the phones was ported that day ( i say 01-04-2013  but customer service says it was  01-06-13 ) i ignored the first notice hoping they would get their business together  been on the road and didn't try get hold of them. So now i talked to Claudia( 03 -2013 ) who told me to check web site customerrelation@familymobile.com  the web site gets you the same as the phone number, nothing. On 03-25-13 i called customer service number erica answered this time and told me the info was incorrect and yes the service should have been cancelled the same day as the porting of phones but they did not and billed me , but she could not issue a credit , she gave me a new web site creditrequest@familymobile.com to get a credit .the web site is about worthless as all their sites.