Renault Parts *******

How can you justify trying to charge me R2100.00 for a part that cost R475.0 18 months ago.I can buy the same part ******* Resistor) in the UK for 27 pounds, around R600.00. I told my wife when we bought the car that I would never buy a Renault again. The car is good but the after sales service is terrible in South Africa.