Is it necessary to change the gearbox oil in my three-year-old Ford Mondeo Sport?

My Ford Mondeo Sport petrol is nearly three years old with 17,000 miles on the clock. During my recent annual service I was told the car required a complete gearbox oil change, recommended by the manufacturers, otherwise the warranty was "null and void". This cost a total of £220 excluding any service costs. Is this necessary?
I presume this has a Powershift transmission. The fluid and microfilter change at two or three years is a standard requirement for Powershifts and also for VAG DSG and S-tronic dual clutch transmissions.
Answered by Honest John on

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