The Consumerist gives kudos to T-Mobile for helping customers on their network through a glitch with iPhones and other unlocked phones even though they don’t officially support the phone. They also gave the customers service credits.
When T-Mobile changed their voicemail system it caused problems with iPhones (and some other unlocked non T-mobile branded phones)
Customers would get blank text messages from the
future (2012!) when people left voicemails, and calling voicemail
caused a flurry of the blank texts to arrive. The customers were charged for the blank text messages.
The T-Mobile rep said that although T-Mobile does not support the iPhone they do support their customers.