Tata original spares are s****

i went to purchase a brand new original radiator fan switch from agents to try solve a 84 years old man Tata indica 1.4 diesel. He told me was already a original, brand new switch. i didn't believe him and never saw any Tata stamp on switch and i thought was pirate spare. I went to order a brand new one and discovered is same shape one. in house when i tested in kettle to see if going on off like I always do with this switches and thermostat I find out is not working, Germiston Tata dealer workshop manager tell me I damaged the switch putting in water in kettle and tell me some more other innocence like always do to any Tata customer and getting away with it. all cars,machines trucks motorbikes fan switch are built to contact with water I purchase one radiator fan switch after market, tested same away. fit on car and when get the switch temperature fan switch on and when drops the temperature a bit switch switch off. switch works between 81 degrees and 71.( not all cars work same temperature) so is not like Tata says they switch works true ecu and bla bla,bla. they looks like they are trying force the old man to fall on they tricks. was saying water pump,radiator,radiator fan, ecu engen , water bottle,damaged because of overheating. The main problem was radiator fan switch give up, brand new one not working too, second brand new one not working too. is no need to go replace everything else if they are in order working condition. they want to ****** people money. the old man is all life been truck driver (a very good one) never overheated / ceased a truck engen or any type of car. if never knew what was doing and fall for this Tata technicians is car would have a s**** engen now. they don't want to give my money back for the switch, they are saying no guarantees on electrical parts. this not acceptable at all and they just proof them self's how they taking peoples money