If you have your services registered in several accounts it is possible to join them.
There may be several reasons: for example you have not been logged in your account and so you have done the registration several times, you transferred the domain to us and the email wasn´t identical with the contact email in your customer account - then is created new account according the data of the CZ NIC database etc.
The process is very simple. You log into the administration
of the account that you want to keep. Then click the link Join Accounts
Then fill login and password of the account that you want to join and click on Proceed
You can join as many accounts as you have and need to.