An oil service is different than a normal oil change. An oil service includes an oil change, adding a fuel treatment, adding an aditive to the washer fluid, checking the level of the trans and rearend fluids and topping off if needed, putting rubber conditioner on all door, trunk and hood seals, lubing all door, trunk and hood hinges, load testing your battery, filling the battery if needed, checking the conditon of the front and rear brakes, topping off coolant, checking all of the lights and replacing bulbs as needed, replacing the interior microfilter(if equiped), checking engine air filter conditon, checking for oil leaks, checking conditon of drive belts and checking tire air pressures including spare.
This is the #1 reason why the older cars start to fall apart. People will see the oil service light on and just get an oil change and turn off the light. If it was me I would pay to have the oil service done at your local BMW shop. It should be under $100 if your car doesn't need any extra parts. BMW put the service lights in their cars for a reason. If you constantly just reset the lights and don't do the required services don't be surprised if a bunch of stuff breaks all around the same time. If you take it in for regular services at a shop they will tell you about small problems that is easly fixed, instead of having something brake and then taking it to a shop and having them tell you it will be a lot more expensive.
I've been a tech for 5 years and a BMW only tech for a little more than a year and a half. I have seen the above situation numerous times and it could of been easly prevented by having regular services done by a qulified tech.