OP - You received a letter with clear instructions to make contact through a designated email address. You have already disregarded that (which will have been noted by Avis). Disregard the advice here to use social media as that will seal the deal.

Either there has been a mistake or you are missing something. But, the folks who issue DNR decisions are not customer service people and they won't mess around. They will be back in touch if your email to them was coherent, short and to the point.

If it was not, start again. Send an email which is no more than 3-4 short declarative sentences. No emotion, no outrage and no reference to your spend. They don't care about the former and they know the latter.

Please report back when you hear. With some specifics, you can get some good advice. Until then you are simply flailing.