AskGamblers is asking you to send a complaint to the regulator of BetPanda casino. I wonder why they don't want to mediate the case.

I don't see a license seal on BetPanda's website with any contact information. It does say the casino is operated by SBM S.R.L, which is Star Bright Media S.R.L, registered and regulated in Costa Rica. You will need to find a way to contact the license issuer. According to this, the company operates under an Anjouan Gaming Authority license. No ideal if that is true, though.
 
You can try to contact them from the following sources:
https://anjouangaming.com/contact/
https://gamingcontrolanjouan.org/contacts/

Please note that the first website states they will not review or respond to complaints sent via their contact form, so the choice is yours.
They suggest sending complaints via the license seal on the casino's website, but as I said earlier, I don't see it. You can contact BetPanda support and ask them how to view their license and seal.