15k of health care claims dating back years, can't even get the claims acknowledged by Cigna

I have lived out of the USA for the majority of the time since 2021. In 2021, I was working a W2 job, and Aetna sent out a check to me to reimburse me for out of network services. The check never arrived and since mid 2021, I've been calling them every couple months to receive a status update. Still don't have the check. I believe it was for mid four figures.

So last year, I was on Cigna Global coverage. I had to go to the ER and spent about 10k out of pocket (doctors were worried I had endocarditis). I submitted the claims right after I left the ER, and I got email confirmation of the claims being submitted. A couple months later, late 2023, I followed up with them through their secure message portal, and through their online chat, and through phone, asking for an update. They said they were working on it.

I called them again in April 2024. They said they would send to the escalation team and get back to me. They didn't. In May of 2024, I contacted my state's insurance division, and they told me to contact a different US agency. I called that agency, and over the phone they were of no help, just telling me 'tHat's whY you HaVe to saVe the ConfirMaTioN of the ClaiMs beIng SubmItted'. I… have email confirmations of all the claims, lol.

So anyways, I post about my experience on social media, and someone from Cigna's social media account gives me an email to reach out to. I reach out to them through email, and someone messages me through their secure portal. They say thanks for submitting, and tell me it will take up to 30 days to get a response back. Surprise, no response back. In fact, in my Cigna account, the claims aren't even showing up under 'submitted claims'.