Send the info certified mail, return receipt requested to the supervisor with a cover letter explaining what's been going on. Make sure you write the tracking number of the certified mail sticker on the actual letter (and each of the other documents), and then make a copy of everything. That way you will have proof that the supervisor received the letter, signed for it, and that you actually sent what you claim to have sent in the letter itself. Send a copy to the claims administrator.
There is obviously something wrong with the claims administrator, and unless you put together a solid audit trail, you won't be able to protect yourself from a subsequent claim that you failed to act within the relevant time period.
This evidence can also get you a lawsuit for damages against the WC agency for negligence in processing your claim.
Hope this helps.
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