At what point do I stop applying to the same company

So I’m an environmental student in my 3rd year. I’ve been applying to this mining company since Jan 2026 for a Summer 2026 co-op (got 1st round interview) then Fall 2026 coop (got 1st round interview). Never heard back from them - but they again posted for the Fall 2026 coop term but this time I finally got a rejection letter literally the next day I applied. (All same position btw environmental science student)

They are now hiring again for Jan 2027 coop term - I’ve got some experience and done a few more courses - got a few certifications - should I keep trying? Or is there such thing as being blacklisted?