About a week ago I purchased a T-Mobile SIM card and activated it on a $3/mo prepaid program. This program requires you to load your account with $3 per month to keep it alive, and these include 30 minutes of talk or 30 messages.
I am using an old T-Mobile G1 (aka HTC Dream, the first Google Phone, I think) as an emergency or an extremely-low-usage phone, so that $3/mo plan fits just my needs right. Because this is such an old phone, the OS is updated to version 1.6 and can't be further updated.
When first loading the account, the minimum amount allowed was $10, so I figured out it should last for some 3 month, which is great.
To my dismay, I soon noticed that the remaining balance in my account was draining very fast, and I expected to be without funds in a couple of days, although I did not make any calls nor sent/received any texts. Chatting and then calling the customer service, I was told that messages were indeed sent from my phone, apparently w/o my knowledge, but they could not tell me who (what) sent them. The representatives promised to block any SMS activity for this account and to refund my lost money.
A few days later, I now have $0 in my account. What changed is that I can now see a few notifications telling me that:
453: Free Msg: Unable to send messages - Message Blocking is active
The 453 seems to be T-Mobile's service number, as I received notifications from 456 telling me that my requested account changes (supposedly the SMS blocking) is now in effect a few days ago.
1. How can I determine what app or process is trying to send SMS's, if the Messaging app does not show any outgoing messages?
2. Why don't the outgoing messages get recorded in the Messages log?
3. How to determine what number is being called (messaged)?
NOTE: A few questions here address similar issues, but unfortunately, the solutions involved installing some permission tracker apps which are incompatible with the old firmware version I have.