The live chat agents can't do anything other then send your issue to the relevant team.
The relevant team is probably a nine to five operation so you have to wait for them to get a response from the team that can handle it the next working day. It's stupid that legal and technical side of things is all normal working hours in a business that has most traffic outside of normal working hours.
There is nothing the support person could personally do, it is not laziness on their part that the people who have the authority to actually investigate an issue won't even be working until the next day.
You are essentially getting irate at a receptionist for an issue you have with a completely different department and she can only ask you to be patient and wait for the bet to be settled, go by the timeframe set out in the T&C's, and if that fails you'd have to contact help again who would, now that the settlement timeframe has passed, forward the issue to the team that can investigate and make any amendments.
Her attitude is completely normal, no matter what you are complaining about, no matter how irate you get, no matter how much you threaten to get them fired, they say
"hello xxxx how are you?"
"congratulations on your win"
"if you have any further issues please don't hesitate to contact us"
"is there anything else I can help you with"
"have a nice day"
"I will forward this to the relevant department"
Even if you personally insult them they will say;
"your feedback is important to us"
"please rate this chat"
The manager is right to back up his staff, she has just given you the standard responses, which you have taken as sarcasm. Understandable; when I have issues and I get pleasantries in response to my gripes I feel like they are taking the piss too, it only seems that way because of your emotional state at the time.
If you were not making a complaint you would get the same pleasantries and they wouldn't feel sarcastic.
You say you got "insulted deeply" - where are the deep insults?
you are just assigning an insulting tone to everything that is been said to you,
You are interpreting her words as insulting. She didn't insult you in any way.
Reading your transcript it looks like you went full Karen. She asked you to wait till the end of the day and see if the bet gets settled, you started calling her lazy and threatening to get her fired.
Then came back the next day to make sure this evil live chat agent gets punished.
Disgusting.
Carry on like that in a landbased casino and security would throw you out.