you have a game ban, not a vac ban. (check your profile)
steam support will not tell you why they gave you the ban.

https://psteamhelp.yuanyoumao.com/faqs/view/46DB-4CEC-F7E9-49E5
the ban is permanent no matter what you say.

ou can’t get a detailed reason for a VAC ban - neither Steam Support nor the anti-cheat will list the exact program or action. VAC records that some software or interference it classified as cheating was used and then applies an automatic, permanent ban that Steam Support cannot remove. If a ban is ever confirmed as a mistake, it is removed automatically by the system, but you can’t request a breakdown of ‘what exactly triggered it’ or a manual review with support