Unfair billing

Unfair billing for older cars of 7 years upwards. They have category A and B. Category A is for cars from 1-6 years. These are brand new cars which come with warranty. Category B are cars 7+years. Now one pays the same premium for both. My car is older so naturally I will take car warranty to help I'm case something breaks. Now im covered for 20% of the total cost of repair while a 1-6years car is covers for full replacement. One pays the same amount mind you. My question is how is it fair to me with an older car who needs warranty more than a person who has a newer car? I was qoated R11k to fix my cluth and this insurance paid R3200. Where will I get the rest of that kind of money. I feel this business practice is morally wrong and I edge if you have an older car avoid them at all cost. They are underwriten by Dotsure insurance.