I haven't seen a service which helps guide someone to pass identity and proof of funds verification on a casino, you can privately reach out to experienced gamblers, some of which you can find on this forum.
I have already completed the KYC procedure a long time ago. What I wanted to ask is if there are companies/people experienced in gambling platforms, who help and give support regarding gambling cases
There will be legal representatives with experience in this area, but that will be an expensive approach and may also be time consuming and if you're not looking to take legal action on the casino it will not be very helpful for the cost. If you're willing to contact someone on the forum, I can recommend one or two members.