Apparently a recent network update caused a few problems for T-Mobile customers who use an unlocked Apple iPhone as the update apparently changed the way voicemail is sent out, and thus customers received blank messages, reports intomobile.
Upon hearing of the problem, T-Mobile answered those customers with unsupported iPhone handsets by offering a little support of their own in the form of resolving the problem in a matter of days rather than the expected six months.
Just goes to show, when a carrier wants to resolve something quickly they can, and even for something like the iPhone which T-Mobile doesn’t sell or even support. Nice one T-Mobile.