The problem with the death penalty in South Africa & how Lex Talionis could fix it.

I'd like to start with a disclaimer & say I have no research in which punishments work in the correction of criminality. 

I'm listening to talk radio in South Africa & heard someone say that "the death penalty does not decrease crime" or something along those lines. Alright, maybe the death penalty would work for people like me (i. e. people who don't want to die) so I'm not sure how it would work for people who do not fear dying & anarchists. Sure, the death penalty should best be used if there is undeniable evidence that someone committed a dreadful crime like murder, mass murder, mass poisonings etc. because we don't want to sentence someone to death with incomplete evidence only to find later that the state killed someone because of a lie someone told. I also do not believe crimes like treason deserve a death sentence today because sometimes the good seem treasonous to corrupt leaders, so the worst punishment a treasonous person could be dealt with is be expelled from the land for an extended period. At times, a death sentence could be given to someone for a crime that truly does not fit his execution because of public sentiment on something & this is where Lex Talionis comes in. 

Lex Talionis, otherwise called "an eye for an eye", is the legal concept that someone should be handed a punishment equal to the crime he or she committed. A CIT robber could get a set amount of lashes & spend the rest of his incarceration working to pay off the amount of damage he committed, a murderer would be punished in being executed the same way he killed his victim, a rapist could be castrated, a person who stole R1000 would get lashes & pay the victim the amount taken... This all might sound funny to some but what is better than being handed the exact action you committed as punishment for the crime you committed? Assault gets assault, theft gets lashes for the thief & repayment to the victim. I imagine a kleptomaniac or a repeat thief could have a finger chopped of for every theft if they could not pay back what they stole. Equal punishment for the crime you committed because doing drugs, theft & murder are not all the same thing & deserve their own unique punishments. And for this reason, I believe thieves, rapists & murderers should be incarcerated in segragated cells & according to the severity of their crime. Because while not paying a parking ticket is disobeying the law, it is not the same as bloodthirsty mass murder.