Sprint/T-Mobile blacklisted my verizon phone

I purchased services with T-Mobile. I brought
my own paid off device (iphone 12 pro max) to
use on the service, along with a series 7 apple
watch i started leasing from T-Mobile. I
decided to upgrade to an iphone 13 pro max,
2 weeks after i started service with T-Mobile, so
sold my 12 pro max to cellfix (a cellphone
store) and bought a 13 pro max from them. 

I put my T-Mobile sim card in my new iphone 13
pro max. I then reset my watch and set it up
with my new phone. I received an email stating
that a change was made to my watch sim and
that if i didnt do it, then i should contact T-
Mobile, but ignore it if I did. I had just
switched my watch to a new phone, so i
ignored it as instructed to. A day later, T-
Mobile had blacklisted my brand new
iphone 13 pro max (which does not belong
to them and was not reported stolen) simply
because they said their fraud system was
triggered by me setting up my new phone
and watch, with my sim card and same
apple id. I spoke to a rep that promised to
fix it and call me back, but they did not do
so. I spoke to a second rep. They stated
that I would not be able to get my phone
back. A $1200 dollar device. I spoke to a
supervisor who demanded i provide proof of purchase, even though the device does
not belong to T-Mobile, and was not
reported as lost or stolen by anyone
because i am the first and only owner. I
spoke to another rep after the supervisor
hung up on me. That rep credited my bill
$25 because i am out of a phone for a
while now. He told me that the back office
team would be removing the blacklist status
but it could take 3 to 5 business days even
though I need my phone for work. I am so
disappointed in this company. What they dis
is theft. They took my ability to use a $1200
device that is rightfully mine. If i had done
that to someone, i would be in jail.