、。
If you're late again, you'll end up losing your job.
Literal
By-chance again tardy-became-[conditional-たら], you [topic-は] job [object-を] lose thing [will-ことになります] [informative-よ].
ことになる ('it comes to be that X,' 'things turn out to X') expresses a consequence or arrangement — often one that results from circumstances rather than the speaker's choice. The polite ことになります phrases the warning as an external inevitability, softer but no less firm than 'you will lose your job.' 職を失う is the formal 'lose one's job.'