The ATTWS problems are NOT due to the portability... It was strictly down to the CRM software they deployed. To be honest, ATTWS was in DIRE need to deploy a single CRM system across all their network regions.
ATTWS still has about a year worth of ticked off customer pain to go through to get things smoothed out.
If I was an ATTWS customer (I am) I would try to do as much as possible via their web front end system to manage, pay or monitor useage on your account.
BTW: Verizon has similar problems when they deployed their CRM system 4 years ago or so.