been a customer for almost 6 years great service, ...

been a customer for almost 6 years great service, never had an issue. Went to have service done message was on dashboard , sticker says service due, came out saw invoice, only a tire rotation done. I should of had oil change like every time I have been there. was told prepaid coupon was for just tire rotation, then why was next service due 5000 miles from now? why was i not asked if oil change was to be done if not covered for first time with prepid service coupons.... very unhappy