Not sure which Tmobile you are referring to. If the US brand, then you will need to call AT&T and get the phones unlocked by them. It's a free service to current and former customers who have completed their contract terms.
If Tmobile in Europe??? We will need to know more why "they can't do anything".
my daughter broke her phone from tmobile and the sim card won't work on the iphone i have 2 of them. i called tmobile they can't to anything to it . they said i have to call apple or apple support line but they will charge me a fee to show me how to unlock so the sim can be use in iphone.?
Apple will not initiate the unlock of your iphone at all.
ONLY AT&T can do this. You would have to call AT&T and ask them if you qualify for this service.