Very disappointed with the service I experienced a...

Very disappointed with the service I experienced at Prestige on my last visit, 3/3/20. Context: I purchased a pre-owned 2016 Audi A6 Quattro in Sept 2018 with 50k miles (not from Prestige). Took it to Prestige for the pre-purchase inspection. Took it to Prestige for two oil changes at it's 5-7k mile intervals with one recall visit between the two. Warranty work was performed on one of the visits. I was not made aware at any visit that there was a 55k mile service to perform that was covered under warranty. I was told on the phone when scheduling the oil change for 3/3, that I had a warranty service available and that could be performed with the oil change. Great! I show up for the appointment and Cory informs me that I have passed the mile marker (69,884) for this warranty work to be approved and I will have to come out of pocket $1,075 for this service. I brought the car in a total of 4 times including the pre-purchase inspection and was never told that this service needed to be performed let alone that it was under warranty. I go to the dealer because I trust their expertise and expect to have an advocate and advisor in my corner speaking from that expertise. Prestige is great about follow up calls to remind you of your appointment and calls after the appointment to which I appreciate. However, why not a courtesy call to remind me of warranty work or making mention of it on one of my previous four visits?? Prestige dropped the ball. They didn't advise me and they didn't give me proper notice so I could prepare and schedule this service within the allotted time allowed. An exception should have been in this scenario and the work should have been completed under the warranty and I should not have come out of pocket for this. I expected better and was severely let down by this experience and will make sure to steer colleagues, family and friends to other options in the future.