It doesn’t exist or is no longer enforced????
Well, there never was an actual “right to refuse service” ever recognized by courts or anything like that. Sure, people have asserted that right, but it had no legal meaning.
However, nobody really needed a “right” before the civil rights laws were passed, because the government simply had no jurisdiction to dictate to private businesses about who they would do business with. Even now, the ability of the government to interfere with private businesses rests on the tenuous assertion that the business is involved in “public accommodation” (originally only applied to businesses such as hotels and restaurants, but greatly expanded by the courts). Alternatively, they can assert that the business is in someway dependent on public funding, which allows them to interfere with the business on these matters as well.