Accounts inactive for 30 days are deleted in low ages (I think)
Your diamonds are still on your master account
I think you should ask support though
Please do not try to participate in every thread, just for your postcount. It does not help if all you do is guess how something works. In the end that is only confusing.
Accounts are not deleted after 30 days of inactivity. Game worlds are deleted. For Stone Age and Bronze Age accounts if the account has less than 301 Diamonds and has been inactive for at least 30 days. For Iron Age and Early Middle Age accounts if the account has less than 50 Diamonds and has been inactive for at least 30 days. Higher age worlds are currently excluded from deletion.
If a game world has been deleted, Support can not put it back.