How can I desauthorise my device with a recovered password?

I have to convert a .acsm file to an .epub file with my ADE program but I cannot because the option of authorising my device is already done, so I am trying to unauthorise my device and authorise back again but the ADE asks me for a password to let me do that, and I already forgot the password. I contacted the technical support and they made me able to recover the password (in fact, to choose another new password) but then I try with this new password and it didn't work either.

Can you tell me what can be the problem?

Thank you very very much!