The Fauna BOI has specific rules for good reason. It is so easy to misunderstand who is writing, who is being reviewed, and who is actually providing the feedback you are looking for without using real names. Cham forums does not do this as we don't venture into that whole arena. I have lurked and read reviews on the BOI for years so understand how they work. You don't have to post a "bad guy" report if you are not sure there's a reason, but you have the option to post an inquiry---or an information post asking others if they have ever dealt with your seller. There's a different post icon to use; either the question mark or the lightbulb. It won't come off as an insult or an accusation that way. If your seller is legit, they should not mind your post at all, as it would give them a chance to respond as well.
Personally, I would also be reluctant to ship a cham cross country during winter (especially this winter!). Just because other breeders will doesn't really help you. Everyone's shipping situation or options are a little different. I wonder if you could negotiate a private agreement with your seller over this. So many of these things fall apart simply because someone gets defensive or feels insulted. There's no reason for this yet IMHO. Part of your deal would be to do the refund to get the PayPal problem out of the way, and agree to complete another sale for this same animal a little later in spring. Is there any reason you have to receive this cham sooner? Believe me I understand you want your animal sooner than later, but putting its life at risk because one of you is uncomfortable isn't worth it.