Im curious what my next move is and whats about to happen. Let me explain the story:

6 weeks ago I took my garbage screen protector off my phone, dropped it, and called aasurion for a claim. They sent me a new phone and I was satisficed for two days until i started realizing that the phone was self shutting off intermittently about once a day. I was also receiving dropped service. So about 4 weeks ago I called to explain. They had me reset the phone which didnt help. I then called back 5 days later and they told me unfortunately they no longer have the S21 ULTRA and would have to cut me a check for the phones worth. I would have to send my phone in and I can move on purchasing a new phone. Well as I was on that call i dropped said phone with no case. I didnt realize how bad it was as the front screens crack was barely noticeable but crossed the whole screen. The back had some glass shatter. At this point my plan was to take it to a phone store and have the screen and back replaced at a cost of $300. Unfortunately no one in my city has replacements and she told me even online are on back order even if i wanted to do it myself. A few days has passed since then due to work and trying to get this taken care of. Now the phone is resetting itself continuously and they're saying its a battery issue. I already received the $1350 check from asurion but they're expecting the phone to be sent back clean.

My plan was to fix it, pay off my remainder of the phone, purchase an s9, do a $800 trade in for an s22 ULTRA. If i call asurion and explain the cracks what will happen then? Does it make the deal void or is there just a charge? What if I dont send the phone back i believe thats also $300?