incorrect e-mail used to set up spotify account and passwords lost for spotify - how do i recover?

[mlfrl]

My son set up an account to take advantage of the 3mo free trial.  i have set up a family acount now, but we cannot access the account my son used to do the free trial - he made a misake in the e-mail registration and has since forgotton his passwords.  I have cancelled his bank details at the banking end to prevent payments when the 3mo free trial expires, but woud rather close off with spotify also. Any advice?