Whats the use of insurance

I just need to vent probably don't understand how these things are supposed to work and i guess all insurance companies are like this and as financed car insurance are mandatory theres no way of evading a situation like mine Ive never claimed by MiWay guess i should consider my self lucky in that regard well that is up until today ,had my car broken into they smashed the window and damaged the inside of my car i lodged a claim spoke to the nice lady and she informed me that my excess is almost R7000 rand , why do i have insurance i ask myself I dont have that money lying around over the span of 5 plus years ive payed them plus minus R20 000 and never claimed i could of payed that money into a bank account and kept it for my car insurance ,Im not completely ******** i know if the car where ****** it that excess wouldnt be that much but hell for damages and a broken glass that seems really unreasonable guess im on the hunt for a new insurance company, happy birthday to me pfft