Yeah they're getting a full time salary amount of work out of you for a contractors amount of work. Its just a matter of having a place to go to. In my experienve tech companies basically never give raises. The only way is to jump jobs. But your company is much bigger than any I've worked at.

now I think I am blacklisted by AI because every time I apply to the same company, even for entry-level positions that pay less than my current salary and I am way overqualified for, I am automatically rejected

I wouldn't take that as evidence of blacklisting. Places will absolutely overlook overqualified candidates. Most will assume you're faking your credentials. Others will assume you'll be difficult to work with. They want someone who is slightly under qualified and desperate and therefore both modable and malleable.