The mileage can’t be “reset” by the dealer and it certainly can’t have a new random figure put in there (17,000 miles)?
I think you have mistaken some other numbers on the display for your mileage and the 17k when it left the dealership after the service in January is the correct figure.
Making a 125+ journey every single day for the last year and a half not only is a mind boggling feat that would put even the busiest of airport taxis in the shade, the fuel cost alone would be astronomical, not to mention the numerous sets of tyres it would have gone through in 67k and brakes etc etc etc.