Turbo

Hi, firstly the year and mileage are probably wrong. Took a guess.
My acceleration became sluggish to non existent. Took to garage they changed oil filter. Said they could not find any problem so turbo needed changing. I could not afford it. So took car back and drove very slowly everywhere. But over the week the car seems to be getting better. Second and third gears are nearly fine again and first is getting a lot better.
Was the garage trying to rip me off?
Cheers, Kris