It was difficult to read the conversation as your screenshot quality is a bit low. I can see that you had warned him to stop sending unnecessary messages, but he continuously complained about the bonus calculation system. He was banned from the chat and discord group of 500Casino. Banning him from the live support system would have ended the issue there, isn’t it?
Terminating user account for such reason is a rare thing in gambling site. I haven't seen this type of rule at any other casino.
Honestly speaking, terminating the account is the last thing the site wants to do, unless left with no other choice. As Suspect mentioned earlier, the user was previously informed that the formula/ algorithm on calculating bonuses and rewards are not publicly revealed, but he wouldn't accept that as an answer and continued behaving in a hostile manner.
Not a nice thing one would want to say to a support rep, given that the VIP himself has access to multiple bonuses (birthdays, weekly, monthly, etc...)
Terminating user account for such reason is a rare thing in gambling site. I haven't seen this type of rule at any other casino.
BetFury does this as well:20.2. If you engage in Prohibited Behaviour, or we determine in our sole discretion that you are engaging in Prohibited Behaviour, your Account and/or your access to or use of the Service may be terminated immediately without notice to you. Legal action may be taken against you by another Customer, other third party, enforcement authorities, and/or us with respect to you having engaged in Prohibited Behaviour.
20.3. Prohibited Behaviour includes, but is not limited to, accessing or using the Service to:
promote or share information that you know is false, misleading, or unlawful;
conduct any unlawful or illegal activity, such as, but not limited to, any activity that furthers or promotes any criminal activity or enterprise, violates another Customer's or any other third party’s privacy or other rights or that creates or spreads computer viruses;
harm minors in any way;
transmit or make available any content that is unlawful, harmful, threatening, abusive, tortuous, defamatory, vulgar, obscene, lewd, violent, hateful, or racially or ethnically or otherwise objectionable;
transmit or make available any content that the user does not have a right to make available under any law or contractual or fiduciary relationship, including without limitation, any content that infringes a third party’s copyright, trademark or other intellectual property and proprietary rights;
transmit or make available any content or material that contains any software virus or other computer or programming code (including HTML) designed to interrupt, destroy or alter the functionality of the Service, its presentation, or any other website, computer software, or hardware;
interfere with, disrupt or reverse engineer the Service in any manner, including, without limitation, intercepting, emulating or redirecting the communication protocols used by us, creating or using cheats, mods or hacks or any other software designed to modify the Service, or using any software that intercepts or collects information from or through the Service;
retrieve or index any information from the Service using any robot or another automated mechanism;
participate in any activity or action that, in the sole and entire unfettered discretion of us results or may result in another Customer being defrauded or scammed;
transmit or make available any unsolicited or unauthorized advertising or mass mailing such as, but not limited to, junk mail, instant messaging, "spam", chain letters, pyramid schemes, or other forms of solicitations;
create Accounts on the Website by automated means or under false or fraudulent pretenses;
impersonate another Customer or any other third party;
using of the cheating and unfair advantages including system malfunction and errors, also using of bots (automatic players) or exploitation of the “errors’;
criminal activities, including money laundering and other criminal intrusions.
As each casino might offer better incentives over the other which is totally understandable, the user has the liberty to play on different sites to suit his/ her specific needs.