T-Mobile Mobile phone service excess fees seattle, Washington

This is a warning to any person or business who might choose to engage with T-Mobile for mobile telephone services.

On the 22nd of February I received an expected and automated SMS from T-Mobile informing me of the need to make a routine monthly payment to continue my pre-paid mobile service. I made an online payment of $50 for a month's pre-paid phone use that day. On the 25th of February I decided to add "International talk & text", for $10, to my service list before I made a call overseas to my elderly mother (cue sad violin music now). I spoke to a representative who said I must be transferred to another department to make the upgrade. The next person took my credit card details four times (he seemed confused and repeated his request for my card number four or five times, at one stage telling me that I was giving him an incorrectcard number - I was not) and then said I was paid up and good to go and "thank you very much". I received an instant automated SMS from my debit card company saying a payment had been made - they're good like that.

The next day I rang my elderly Mum overseas to wish her a happy birthday. Part way through the call (about ten minutes) the phone died and I instantly received an SMS from T-Mobile stating that I needed to pay for additional services. Needing to complete the call I went to T-Mobile's app on my Android device and noted that I had (curiously) used up my allotted amount of time/money. I needed to complete the call so I applied a second online (via their app) payment of $50 to my account and continued with my call. Surprised once again was I when my call was terminated mid-way. I checked my T-Mobile online account and was surprised to find that instead of removing $10 for "Int'l Tlk&Tx", T-Mobile had simply removed $50 and not added the required service. I rang them today and spoke to a somewhat helpful but slightly too efficient person (with a heavily-accented English that required great stamina to comprehend) who insisted that T-Mobile had done what I'd requested. She then informed me that through her records she could see that not only had they removed $50 from my debit card each time but in fact they'd removed an additional $50 instead of the $10 fee for "Int'l tlk&Txt" and in fact had not added that service. She offered no quarter in her insistence that they'd done what I'd asked for. I told her what I thought of their practices (this was not the first time I'd had to clarify payment or service or register a complaint with them about their not fulfilling an agreement. Finally, exasperated, I politely told her I was going to hang up and vowed to switch carriers the same day.
The end result is that T-Mobile removed $50 from my debit card with a space of five days, did not give me the service I'd clearly requested, and offered no apology or explanantion for the additionbal fees other than they had no record of my request and that I was the one using up my alloted time. How can one trust a company which does n ot do what they say they will do (and takes a fee too) and then says thye have no record of the request or transaction.

Buyer beware!?