I want a new turbo charger or refund

Qoute no. 135227 On the 23/05/2019 i took my turbo charger for recondition when i get there the price for the new and my old turbo charger to be recondition was almost the same the same i decided to buy a new one at amount R4300.On the 26/05/2019 i went to fetch it took it to the mechanic to put it mechanic changed oil, oil filter and air filter. I drove since then on the 30/06/2019 on my way back from Mapumalanga to Johannesburg when i reach Middleburg i heard a funny noise i stopped to check i found that the oil was going to the exhausts. I called someone to come tow the car to my house in Johannesburg on the 01/07/2019 i took the part back to them they told me they need to investigate few days they called me back advised is not their fault they sent me the report according to their report the damage displayed by the unit was caused by the foreign object passing the turbo. They want me to pay again R2785 first to assist me. According to the receipt the part has 12 months warranty is not yet 3 months the company refuses to assist.