Thanks for your reply.
To be honest I don't know when I registered at ZoneEdit. I can only say that on the date you mention I was about to create a new account when I found this handle in my notes and I was surprised that the account still existed and that I could still enter it using the password I had in my notes too. I haven't used this handle nor this password format recently for other registration purposes.
I had to create a new account to enter this forum, that's for sure, but that's only a few days ago. The handle for zoneedit.com didn't work here.
As I said I don't remember when I registered at ZoneEdit and I didn't record the date either. I've started doing so more recently. If you say It was on 14 Mar. 2018 you must be right. Anyway, I can't prove otherwise. I still think I registered many years ago, maybe even in 2006 when I finally found a free domain which included free DNS service and I forgot about this account.
But hey, beggars can't be choosers, so I would be perfectly happy with three free DNS domains hosted with ZoneEdit and if that's impossible I'll continue to use ZoneEdit free DNS service for just one domain, no problem.