This isn't a scam at all. That's exactly what you'd expect from insurance. Insurance isn't there to save you money. In fact, the expected value of an insurance plan is always going to be negative on an infinite time horizon[0].
The whole point of an insurance plan is to smooth risk: instead of the small possibility of a catastrophic failure, you take the relative certainty of having a fixed monthly payment (your premium). At a very high level, it's sort of similar to taking on consumer debt (credit card debt): in the long run, you'll always pay more than if you just paid cash up-front, because of the interest. The difference between credit cards and insurance is that you don't know when the expensive event is going to happen, so you agree to always pay the monthly payment regardless of what happens. And while banks charge interest based on the risk that you won't pay back and the opportunity cost of that money, insurers charge you a premium in exchange for the luxury of not having to guess whether next month will have an expensive event or not.
In your friend's case, the fact that she had two claims adjusted her relative risk profile, which means that her premium had to adjust accordingly.
[0] If it weren't, there'd be no point to going into business as an insurer, because you'd be guaranteed to make an operating loss. The only way you'd be able to make any money is based on the investments that you make, at which point you might as well eliminate the insurance side of your business and operate as a bank. (Interestingly, this is why the relationships between banks and insurers are so close in many countries, and also why most insurance markets - car insurance and health insurance[1] being two notable exceptions - have surprisingly slim profit margins).
[1] Health insurance is a special case because, strictly speaking, it's not really "insurance", but that's a whole separate discussion.