I had a similar situation back when Adobe lost their database. I have a personal domain with a catch all configured. So back then I would just give a name like

I had a similar situation back when Adobe lost their database. I have a personal domain with a catch all configured. So back then I would just give a name like adobe.com@<personal-domain>. When they leaked my password I contacted their support and they flatly told me that's not them who lost the password, even though evidently the mail itself was tailored specifically for Adobe. It is likely the support was told to follow a script when a concerned client contacts them and there is no way they are going to tell you anything else regardless of the specifics of your case or how absurd their arguments are.