Unable to Access my Zoho Invoice account

Unable to Access my Zoho Invoice account

I erroneously removed the main email address for our Zoho Invoice account during a Zoho Mail setup and now I can no longer login to the Zoho Invoice account to which the email is associated. We had recently made a payment for the Zoho Invoice account in question and now we are unable to use same due to this issue.

I'm really stuck and would appreciate if any could provide a timely help with this issue. 

Thank you.