What would you do if you had a new mobile phone and new SIM card but you...

...still unable to use it? I signed a contract with T-Mobile on the 14th of August and wanted to keep my old phone number but it looks like they had problems to unlock my SIM card 3 moths have gone and they are still unable to provide me with the service I signed for now I can not use my old mobile phone neither my new one. Would you go back to T-Mobile shop and cancel the contract you signed with them?

Yes, before that you can try for a free unlock from sources like Unlock-free.com or a paid unlock service from Simpleunlocking.com by mentioning the phone make,model,country,locked network.