How old is your online casino running? Does all coins deposited to our CSGOPolygon sallet converted into your CHIPS?
Do you allow the use of VPN for the use of accessing game not available to the region?
Based from whois, they were registered 2016, but don't know if they were already active at that time.
But at the bottom of their site, it says 2016-2021.
https://www.whois.com/whois/csgopolygon.com
Maybe you can read their FAQ section so you will understand better about your deposit - https://csgopolygon.com/faq.php#faq_a3
About the use of VPN, it is better to read their ToS - https://csgopolygon.com/tos.php
There are restricted countries on their list and I don't think it is good idea to use VPN if you are residing on their restricted countries, based on item 6.2
It says, it is not allowed to open accounts if you are residing in those mentioned areas. If you proceed, I guess, you may encounter trouble later on, so better not to use VPN in my opinion.