Based on these two information alone, I do not believe you should be unblacklisted from SCHP 527. According to Crystal, a Senior Moderator on our server, you were caught in D block as 280 which is a clear violation of rules. Whether it was you or not, you have this history of violating SCP Rules constantly.
According to our motd, "SCPs 131-A, 131-B, 343, 527, and 1424 are allowed to go into D-Block. However, these SCPs are not allowed to step onto the elevator or enter lower D-Block". It says so in the rules. The fact that you said you didn't see any signs tells me that you didn't read the rules at all either.
Absolute -Support