Ban is a month old not a week.
2. You have no idea when cheats were detected by VAC as it's bans can be delayed days, weeks and even months.
3. Overwatch results in game bans not VAC. They are not the same. If Overwatch did ban you you got caught by 2 different anti cheat systems.
4. VAC has no idea who you killed or how you killed them. Killing through a wall in itself doesn't mean a person is cheating.
5. Click and read the INFO link on your profile

1 VAC ban on record | Info <-------------CLICK HERE
31 day(s) since last ban