Disaster at Hiring Processes - Senior Data Scientist NET CHECK Employee Review

I was rejected with a signed contract. Disaster - that's what I can say about the hiring processes at NET CHECK GmbH. I passed all interviews. I clarified all details about my responsibilities and my contract. CEO and I signed the contract. The notebook and signed contract for Visa were “sent” to me by post. It's been a while since the last status update, so I decided to check up with the hiring manager but was ghosted, I've got no replies for my follow-ups. This lasted for five days until I contacted CTO to clarify what had happened. He replied in three sentences that they wanted to find a more experienced Data Scientist in the domain. There are no condolences and no meetings to explain the situation. I’ll tell you more: they posted a job on Linkedin a week before I wrote to them. They knew about my status and decided to behave even worse. The story had been going on for about a month, and of course, the rest of my offers had gone stale.