BMW has become ENTITLED and avoids warranties - I AM DONE WITH BMW

I have had my BMW X3 for 11 years. Done all servics and battery changes as normal. Car was suddnely sluggish first thing in the morning and I asked a garage nearby to check it for me and they advised that the battery may be the issue and as it was under gaurentee from BMW tro reather take it to BMW for investigation which is exactly what I did. BMW sent the battery to Battery Centre which recharged battery and after 2 days reported nothing was wrong. BMW said nothing on the car was wrong either as per diagnostic checks and it must be a 3rd party accessory, a Tracker device causing the issue. Discovery Insure sent out the Tracker people who also found nothing wrong on their side but changed the setting on the tracker to go to sleep mode if the car was not on just as a precaution. BMW told me to collect the care and to monitor and come back if there were any further issues so they woudl take it up with Battery Centre again. Suddenly 2 days later BMW calls to say that I must remember that as they couldnt find anything wrong it is because i am not driving enough and must drive each week a good distance (she mentioned twice is must be more than 60kms/trip) to ensure the battery charges or I must buy a trickle charger to charge the battery. I was very VERY upset and argued why after 11 years of the same driving suddenly now, when this battery change is under warranty, that I now get this arb call? Its seemed to me that they were "covering their ****s" to put it plainly. They argued that my car is old and newer tech doesnt hold the same problems. But then how have I survived 11 years on the 'old tech' and never had an issue? I argued that there are many families that have BMWs that the wife uses to drive their kids to school and back and pop down to the shops so they then shouldnt be driving BMW's if their daily mileage is too low? Perhaps I should warn them thereof on FB or something as surely this must be highlighted to thoise using their cars for local driving. I was then told they (BMW) are not making excuses so I asked them outright... so if my car continues giving battery problems under this waranty what would they do if I brought it back like they said I could. The answer --- I would need to pay as I dont drive enough. I ended saying I will trade my car in on another brand and that BMW will never have me as a client again. They had just confirmed that they are covering their ****s. They didnt seem to care. Clearly they have enough Corporte and Government business to not worry about the normal person. I am livid.. For me? BMW doesnt care anymore. They can keep their shining upmarket offices and cappucinos... I would rather have a brand that cares for the individual and doesnt look for excuses.