TTIG - Working but without access to the gateway

Hey together,

wishing all members of this forum a Happy New Year.

I hope you can help me to solve my issue. I bought a TTIG device and registered it to my private TTN account. At first time it seemed to be not working and so I tried to connect this gateway to another account. After type in the right data to my business account the gateway was also without function because the device was successful registered to my private account which I deleted due to the issues. I haven’t now access to it. The gateway is now working and active in TTN, but without administrator.
Is it possible to reactivate my deleted account or is it possible to delete the device from the network so that I can register the device again.

I have the same issue with two devices which were registered with my deleted account. Is it possible to delete the devices with admin rights out of the network?
I have all necessary keys to show that I am the owner of the devices.

Many thanks in advance.