Apple Customer Service

Over the Years I've had occasional periods of owning Apple products and last September when My Wife needed a Cell Phone upgrade, We splurged and signed onto the AT&T iPhone plan. At first She wasn't sure about all the features but eventually has learned to embrace it. UnTil about three weeks ago has been working great, but started to have no bars signal strength and constantly " searching" for service. We first went to AT&T and they replaced the Sim card and did the "big reset", but continued to experience problems so next talked to Apple Support.
Now We have several other AT&T service Cell phones and they were experiencing no problems and We informed Apple of this. They had Us do a "master reset" and after several days problem still exsisted so contacted them again. Heres where the story usually gets be to depressing, but not this time! Apple support talked to Us and We tried reloading default config after saving original to iTunes and eventually the conclusion was -- bad iPhone. New iPhone was sent to Us within Days with better instructions than I've ever seen on changing Sim,putting old phone back to default and loading the new phone from backup iTunes. It also was detailed on the return procedure!
The new IPhone works like a champ and Apple receives Kudos from Us . Great customer service, hope it stays that way. Thanks Mr. Jobs!!