A 1099-MISC is not required for you to report the royalty income you actually received in 2019. Not having a 1099-MISC does *not* negate your requirement to report the income.
Being that you only have two weeks before the tax filing deadline, you're really cutting this close. I would suggest one last attempt to contact the company. If that fails, then legal representation is called for here. Additionally, if you did not receive the checks "IN 2019" then you are not required to, or expected to report the income on your 2019 tax return.
Were it me getting a "runaround", they'd only run me around that track for one lap. After that, they'll be the ones running to make things right pending legal action. I've had similar experiences in the past. But I don't let it get this far before I have my family lawyer type up a firm but polite letter that is "requesting" they make things right immediately, or risk the unfortunate expense of paying my lawyer in addition to a judge ordering them to make things right. Of course, before going such a route you have to make absolutely certain that you've got your ducks in a row.This is why I recommend anyone with anything of value always have a "family lawyer" on retainer. For me, it's only $25/mo.