Question about etiquette for demanding refund

[Will0W783]

I had another thread about "Spilotes pullatus cloaca problem" and this is regarding my efforts to get a refund as the snake died within 24 hours. The seller at the reptile show where I bought it on August 1 had given me a 14-day health and survival guarantee. I paid via Paypal right there at his booth. However when I brought the animal home it was severely dehydrated and looked to have a cloaca infection and died the next day. I contacted the seller first about the infection and he was very helpful. However when the animal died he stopped returning my calls and emails. I've been able to catch him on the phone twice since and first he offered to replace the animal but I demanded pictures of the head and cloaca of any replacement animal before I would take it. Then he said his son sold all the other ones so he would go online and give me a Paypal refund. I spoke with him August 6 and he said he had had a tornado hit his house and was waiting for insurance adjusters but still had his business running. He told me he would go online and refund me right away. Now it is August 12 and I haven't heard anything from him, nor have I gotten my refund. I would like to think he is just overwhelmed, but I am starting to worry that he has no intention of refunding me. How long should I wait before I threaten to take it through Paypal and the Fauna BOI? I don't want to be hasty, but I also don't want to be screwed over.