BMW R 1250 GS Adv Service Overcharging

I took my R 1250 GS Adv motorcycle with license plate 35 *** 319 to Ozgorkey BMW authorized service on 06/19/2023 for its 1000 km maintenance. Despite seeking confirmation from my Istanbul friends, when I learned from Mr. G** that the service fee was applied as 5200 TL during the service record opening, they insisted it was the standard rate. Despite the increased exchange rates, my friend who owns the same year and model motorcycle had the same 1000 km maintenance 16 days after me. This practice has shaken my faith in BMW as a trustworthy brand. I want to emphasize that the amount is not the most important consideration. However, even minor issues can be off-putting. This appears to me to be an application error within the BMW corporate structure. I anticipate that necessary infrastructure improvements will be made to prevent the recurrence of such errors, and I kindly request your prompt action and clarification on the matter.