Oh that's sad times if it just stops working all of a sudden. I would start by making sure all the settings are correct based on what you see on our Generic T-Mobile data settings doc. I would then power off the device, turn it back on, then test you data first. If the data is working, give the MMS a try. To eliminate the phone as a possible cause, you could test the sim in a T-Mobile device and see if it works.
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