walmart family mobile did not cancel service, could not port number, kept billing, sent notice they would turn account to colletor, Internet

I called them and canceled service.  I went five weeks without a phone because the new company could not port the number.   I blamed the new company,  later wamart familly mobile sent a bill.  I called, they wanted my ss number.  They said they would send my account to collections, said I had not confirmed the cancel.  They sent a letter saying they would send the account to collections.  I think the law requires that they allow the number to be ported.   I will not pay for the service after I called and canceled.  no one said that I needed to confirm.