XC90: Speedometer had been changed on the car?

[canitez]

Hello everyone, this is my first message, and I bought myself a 2019 Volvo XC90. I want to ask for your opinion without prolonging the matter. When I checked the MOT details of the car, it had been inspected with 28 thousand miles on the clock in October, but as of March 1, it shows 80 thousand miles. I asked the seller, and they said they had no information about this. It seemed strange to me because covering 50 thousand miles in such a short time is quite challenging. Anyway, while reading the car's manual, I found an invoice inside. According to the information written on it, on January 30, 2024, the faulty speedometer was replaced with another one. The faulty one had 46 thousand miles on it, while the replacement one shows 80 thousand miles. It is said that it needs to be taken to the main dealer to get it adjusted because it has a blocker on it. Now, I'm a bit puzzled and wondering if anyone among you can provide information on what I should do. Additionally, do you have an idea of how much it might cost? I want it to be solved -if it is possible- before the car MOT checks which current millage on the system will be updated, Thank you.