Well this is nice of T-Mobile and shows they do somewhat care about customer service. I can chime in and add my experience with the English (American?) division of T-Mobile: they responded to a mention at a social network while I was not even really meaning to ask them a question, I merely mentioned them. The Dutch division is not as great, but oh well.
Still, I'd say it's how it's supposed to be. In the Netherlands it'd be illegal to upgrade contracts like this. You can't start charging more without giving the user an option to quit the contract for free (or continue the old contract for the old price). Also after the contract period (one or two years), consumers have a right to cancel the contract each month, also for free.