Cell C "customer care" service

Good day, @cell c In the digital savvy and ever changing world that we live in, How is it possible for a network provider to ask for last dialed numbers, when you the ower of the pre-paid account wants to block a number because he/she was ******. When you walk into a cell c outlet and AK for sum swap, you have to know the last dialed number, or they are u able to block or do Sim swap for you. Are they the only network provider that that doesn't know that, in day and age we dial name and not number. When we go through our phone book, up pops a name to dial, we don't physically type in numbers anymore. I mean waht is the purpose of a RICA. I have another provider, Telkom, Thank God for them, because when you provide them with you information the account was RICA with, never have you to remember anything else. Cell C is such an inconvenience, making my life unnecessarily difficult. All I want to do is block a number, because my son got ******. I am sure there is a "thousand", questions you can ask to verify. Again why do you take me personal details to RICA an account if you're not gonna used and just go around asking for last dialed numbers or frequently dialed number... I DON'T K OW THEM, ALL I KNOW IS THE LAST DIALED NAMES AND FREQUENTLY DIALED NAMES...