Transfer pin

I was behind on my bill. I made a payment arrangement. However, my checking account had some unauthorized purchases so my card and account was changed. During this time my payment arrangement payment was not able to come out. So they canceled it an said I was not able to make another arrangement and required all the money at one time. I could not afford this. I tried to get new service to have phone for safety while I'm paying them off. However, they would not give me a transfer pin until I paid all the money I would. That number belonged to me and the held it hostage. I'm pretty sure it's against the law to block a number from being transferred. Am I wrong?