Kids syncup won't turn on

I went to another carrier. I contacted the manufacturer who said it was a programming error and T-Mobile should replace the watch. T-Mobile told me they did not see my insurance on file, which I purchased. There is paperwork in my email. Ultimately T-Mobile told me they would not replace the watch and fully expected me to pay for a line I could not use. I went to another carrier where I got my daughter a phone with parental controls. T-Mobile said they were going to bill me the full cost of the watch. 2 months after I was no longer a T-Mobile customer they made an unauthorized charge in my bank account for the full cost of the watch. I have had T-Mobile for over ten years, now that I am gone I will NEVER return. I've tried to post a response several times. Let's hope this one sticks.