Stop feeding the monkeys and don't allow anyone in your neighbourhood to do so. Try explaining the problems feeding vervets can cause.
Do not encourage them to come close to people, especially young children.
Keep windows and rubbish bins securely closed and fastened. Minimise the sight of food and you solve your problem.
Condition monkeys not to come onto your property by using a catapult with small cubes of potato. this will not harm the monkeys.