[mothered]

"I haven't had time to check any other carriers with all of the hysteria happening, it's hard to find a chance to visit a carrier. In that time, the battery hasn't gotten worse but it's still very bad. Are you sure this is safe to ship?" Something like this?

Under the circumstances, this seems very appropriate.

How long has It been since their last reply?

5 days since his and 4 days since my last email.

They're probably thinking you'll simply give up, and not pursue the claim any further.

Time to hit them with your above reply.