Requesting a cross-account Xfinity Mobile line transfer from my mother's account to my new account. Device is fully paid off and active

Requesting a cross-account Xfinity Mobile line transfer from my mother's account to my new account. Device is fully paid off and active for 2+ years, but phone support keeps telling me to wait. I called mobile care 6-7 times. Each billing agent told me that I had to wait 24-48 hours. I called back each time but couldn’t figure it out. They  finally sent me to the line-to-line transfer department. But they told me that they couldn’t do it because whoever initiated it caused an issue and I had to wait up to two weeks. I don’t get it. 

I did some research and my mom is on an older plan. I believe this may be causing an issue. I just started my plan under my account and I want get my line onto my own plan. Please do not give me a run around and please resolve this issue. For some reason, Xfinity had no problem transferring a different Verizon line onto my account but is struggling to transfer an Xfinity line to another account.