Hi there,
An e-mail can only belong to one account, even if that account has been disabled. You will have to contact our customer support to help you out with this. You can find our support through the below link.
https://support.onlinesoccermanager.com/hc/en-us
After that, click on 'submit a request' and choose the option 'OSM' to fill in the contact sheet. Make sure to provide the manager names of both you current account and the account that you disabled.