I have had the exact same T-Mobile account and plans for more than 10 years now, and I have seen my monthly bill go from ~$82 to ~$86 today because of additional fees. The bulk of my plan has been the exact same, just additional or increased fees for the extra $4. It's not much money, but it's the principle that they can adjust my costs upwards without me consenting, essentially forever, that pisses me off.