Something positive to report.
It seems to me that T-Mobile is actually treating its customers fairly. At the weekend my friend in Glasgow phoned me up and after a few minutes the signal was lost and so he left me a voicemail to finish the conversation.
I've just checked my credit balance on the phone and it seems that I haven't been charged for the retrieval of the voicemail message.
Well that's great news. Not too many cell phone companies would omit a charge. Seems like they charge for everything!