how to unlock my cell phone

You need to be a customer of Tmobile and meet the requirements in the link below.

https://www.t-mobile.com/responsibility/consumer-info/policies/sim-unlock-policy

It was, but I'm already in Colombia and I brought the phone, but it's with the bands closed, it's only good for t mobile, what can I do? Is there an email where I can write to open them?

you can try through one of their social media platforms like Facebook or Twitter. did you purchase the phone from someone else that was with TMO or you were with TMO and didnt unlock it before you left to Colombia?

my aunt was with t mobile before coming back here to colombia she gave it to me as a gift but there came a time when the bands were no longer playing and i started to find out then that's why i'm writing here because they told us that we could access an email that way where the mobile data was sent and we waited for them to answer us

You're aunt needs to contact Tmobile support to request the unlock code.

how can you contact support she is here with me pending

either by calling TMO or through one of their social media platforms like Facebook or Twitter..the FB/Twitter route lands you with tier 2 support instead of the call in tier 1 support..

If it's a Tmobile device you can call the international number in the contact us page.

https://www.t-mobile.com/contact-us

good day can you give me a support email

There is no support email.