Merging Accounts

I have been using Zoho for a while. Recently, I started using Zoho Campaigns and I added myself and several co-workers as users. It turns out that one of them has already made himself a user on his own account. Now I can't add him to mine and he can't add me to his because both our email addresses are already in use. I don't want to close my account completely because I have data on CRM that I cannot lose. What can I do?