Sandbox Interactive complaint: Deleting my account instead of changing my account details

Hello, basically what happened is that I am switching my email account for privacy reasons and I want to go away from Gmail to some other email provider.

All other gaming companies normally allows this change just using their website, only one other game so far needed me to contact support but it was dealt with swiftly and without any issues, all it took was to prove who I am.

I’ve contacted Sandbox Interactive support (about their game Albion Online) to ask for the same. to simply change my email address from one email to another. They’ve asked me why and I responded that I am no longer happy with my current email provider.

Their response was to deny my request. I couldn’t believe it and replied that rather than to have my account frozen, with my data on it and not able to use it once I abandon this gmail email… I would prefer to have all my data removed from their system.

They asked for ation if I want to have it deleted, and I said that I DON’T want to have my account deleted, that I want an email change.

After that their last response was that my account is now banned and in process of deleting.

I’ve bought this game in their crowdfunding campaign, became one of their founders and even bought it as a gift to a friend of mine and my brother, I didn’t complain when their game wasn’t solo player friendly as they promised it will be. Yet, after basically zero cooperation from their support staff, I am loosing this account that I invested in no small amount of money, with no other options. Sandbox Interactive basically tells me that I have to use either a service I don’t trust for my email, or lose my digital property in their game.

I don’t know what else should I do.