All of suden when, my went blacklisted!

This forum is not customer support and “i did lost it for Min between then and now” makes no sense. In any event, you need to contact customer support directly.

Thanks for reaching out to us @Dbuxtr

Tell us more about your device!

• What do you mean by "all of a sudden, your phone went blacklisted'?
• Is the device you're using is AT&T-branded and currently active with the AT&T cellular network?
• Was the device previously reported lost or stolen? Have you recovered the cellphone and is trying to have it removed from blacklist?
• Do you currently have wireless service with AT&T?

Provide is us the specific details to help determine what's happening. 

We kindly await your response!

Dwight, AT&T Community Specialist 

Yes, hi my name is Julio, I resently activated this phone to the 30 plan, however, I had paid for the 10$ prepaid sim. At target. I had been used this phone with t-mobile, but lost the SIM card now I had put the sim but I need it an account, took it to AT&T’s and they activated and paid 45$

but when I call said this device is blocked from the network.

Help please, thank you

How do you know AT&T blacklisted it?  If you previously used the phone with T-mobile, maybe T-mobile blacklisted it.

In any case, are you the original owner of the phone?  If you bought it from someone else, they may have skipped out on paying for the phone or reported it lost or stolen.