Cost of a Repair

Please explain to me why the cost of doing a repair is more than buying a brand new phone, of the same make.

Vodacom confirmed a Huawei p20 lite costs R4999 brand new (Other places are even cheaper than this). The quote for repairing my 4 month other p20 lite is R5520.38.

When I queried this with customer care I was told "It is what it is", and "This is the cost". But that's not an answer. The cost did not naturally occur in nature. A Person set this cost, why cant a person change the cost of a repair to something more reasonable and fair. Otherwise, please provide a detailed description of what the R5520 consists of because this pricing structure doesn't make sense to me.