Go Smart Mobile Customer Service Issues

I recently switched from being on my boyfriend's T-Mobile plan to QuickLink Wireless in September [redacted]. I settled the outstanding amount for my iPhone SE with T-Mobile to keep my number. Despite the initial hassle to release my number, I was satisfied with QuickLink's service, especially being on a fixed income. Around May 9th, [redacted], after returning from the hospital for pneumonia, my phone suddenly displayed "SOS" and "NO SIM," rendering it unable to make or receive calls or texts. Despite reaching out via chats and emails to QuickLink, they explained my number had reverted to T-Mobile without authorization. In an attempt to resolve this, T-Mobile informed me I was not on their plan and redirected me to Go Smart prepaid service, which is not suitable for my needs. Facing upcoming cancer treatment, connecting with my medical team is crucial. I am distressed by this unforeseen issue and seek assistance to rectify it promptly.

I recently got my phone number back, but I haven't been able to use it since then. I've paid my bill for the last two months, and I tried switching my SIM card to a new phone as advised, but it still doesn't work. I was told to put the SIM card back in my old phone, which I did, but the issue persists. I've been disconnected multiple times today and faced with the news that the company is now closed. Can anyone assist me with this problem?