Stealing your hard-earned cash or anything that you might have given them anyway, had they asked... it's just hurtful.
When a child, an older child, begins a destructive cycle of lying and cheating, they are focused less on getting back at you and more likely interested in something outside.
To think that a child is going to risk getting caught just to make you angry is a little self-centered on your part. They are covering up another activity or spending money elsewhere.
There really is little concern about upsetting you as their priorities have completely shifted away from the home. Unfortunately, this often occurs due to some external driving force that may be somewhat addictive.
To be sure, a study of their related behaviours before this activity started is called for. It will help determine if the cycle is short-lived and if the child can rebound, or if the activity is simply the topping on the cake and became a reason to abandon all concern and respect.
Sad to say, each case is different, and we cannot diagnose what you may be encountering via the Internet.
Tougher still is the fact that bending to their every whim as a means of having them stay home safe and sound only weakens your position in their eyes. Your existence as a target of respect is nullified and cannot be recovered for years, if at all.
It is best to seek out professional help for yourself in order to assess the best treatment for your child. I would never propose having a parent force a child into therapy without the parent first having undergone an extensive assessment.
All too often, a therapist will find the root of a child's
problem lies in a parent, so don't waste time avoiding the inevitable.