This Operation has been restricted. Please contact support@zohomail.com for further details

This Operation has been restricted. Please contact support@zohomail.com for further details

Yesterday I added a new domain kello.pl. Today I tried to verify it and I got the error message: This Operation has been restricted. Please contact support@zohomail.com for further details.
So I deleted the domain and tried to add it again but the same error still exists. I receive also the same error when I try to make any domain a primary domain.
Is this a joke? I have a subscription.