SP Group Software Engineer, Backend interview questions

After a referral, recruiter reached out with a coding challenge that was to be completed by a certain deadline (with a requirement to timebox myself and use maximum 12h). I was to create a Github repository and share access to their engineers upon completion. 4 months later, the invitations to the engineers are still "Awaiting Response". I'd totally get it if the code was substandard and they communicated their decision to not move forward with my application, but this wasn't the case. I feel it's such a waste of everyone's time and effort if the engineers weren't going to review the code in the first place. It shows a horrible disrespect to the candidate and the degree of unprofessionalism in their recruitment process.