I'd like to unlock my phone

What make and model phone do you have and where and when did you buy it?

depending on if you jumped onto pre paid or post paid there will be certain things that must be met to get it unlocked.

Unlock eligibility for mobile devices on Postpaid plans

• The device must have been active on the T‑Mobile network for at least 40 days on the requesting line.
• If the device was financed or leased through T‑Mobile then all payments must be satisfied and the device must be paid in full.
• If the device is associated with a canceled account, then the account balance must be zero.
• T‑Mobile may request proof of purchase or additional information in its discretion and certain other exceptions may apply.

Unlock eligibility for mobile devices on Prepaid plans

• At least  365 days  must have passed since the device was activated on the T Mobile network.
• If the device was activated less than 365 days ago, then the   Prepaid account associated with the device must have had more than $100 in refills during that period for each line active on the account.  In   addition, more than 14 days must have passed since the device was purchased.
• No more than 2 mobile device unlocks have been complete per line of service in the last 12 months.
• T‑Mobile may request proof of purchase or additional information in its discretion and certain other exceptions may apply.

I think I’m in this case, unfortunately I paid only for 1 month and I have active on it for only 2 weeks (just for holidays) So it sounds that I’m not eligible. I don’t understand how they can have the right to lock a device which has nothing to do with them. I just wanted to be able to use internet at there. 

“It sounds like it had only been temporary unlocked when you purchased it. “
No, I bought it fully unlocked. T-mobile doesn’t even exists in France, where I bought this phone, so I don’t think it’s possible that it used to be locked by T-mobile before I bought it. The sim card automatically installed the t-mobile apps on my phone without asking me, and it got locked. I can still use my french sim card, and most of the time the t-mobile lock doesn’t annoy me, but I can’t uninstall the apps and it causes me troubles when I go abroad.

So it sounds that I can’t get rid of it as I’m not eligible for the unlock process. I don’t get what is the point for T-mobile to do that but anyway thank you all for your answers.