Pathetic Unprofessional Service (Vehicle in dealership for over 1 month)

Horrible and utterly unprofessional service from this dealership.My vehicle (with 37000km on the clock) had a battery issue.The car went to the dealership over 2 months ago.The Battery was replaced 2 days later (bear in mind it takes battery center about 15 minutes to do this) nevertheless I was asked to collect my vehicle by the service adviser Tracey.Picked the vehicle up on the Friday afternoon just after 5pm and after driving under 1km from the dealership,the vehicle went into limp mode and began misfiring (remember this vehicle only has 37000km on the clock).We managed to drive the vehicle home and tried contacting mercedes, we were told to bring the vehicle to them.On Monday the service adviser requested that we need to get hold of mercedes assist to take the vehicle to the dealership surely this should have been done by the "service" advisor.Nevertheless we took the time as a customer to drive the vehicle to the dealership ourselves.We were then advised that the issue is due to the spark plugs and is a "fueling" issue and is not covered by mercedes we were then given a bill of R5k to pay for new plugs on a car that has a full active Warrenty with mercedes.After numerous calls,The "Service" adviser then said they would check the plugs again after we requested a report stating that the issue is due to fueling.To date this has never materialised.It is now over a month later with absolutely no feedback from the dealership regarding a report,no curtesy vehicle (as this is apparently not a mercedes issue).We have escalated the issue to mercedes Benz complaints last month who have never contacted us via email or call and state that they are still waiting for the dealership report (for over 1 month 😀).It's not about the money,it's about doing honest business with ethics towards your customers and clients.Mercedes should start advising all mercedes owners where they should be filling fuel in future because clearly their vehicles don't have decent quality fuel filters in place if the plugs are getting damaged so quickly? We have been loyal to the brand for the past 50+ years but this experience was nothing short of pathetic and is a poor and bad representation of the brand by NMI Umhlanga. They have absolutely no regard for customer service,the Hellopeter reviews around the dealership speaks volumes about the service.I honestly wish I took my vehicle to another mercedes dealership.Seems like a little money making **** to make clients fork out cash to replace spark plugs due to "fueling". No diagnostic report to date either.The location of the Dealership is what actually carries this dealership.I wouldn't advise anyone to take your vehicle to them.Rather go to another dealership and give them your business.After escalating to Mercedes Benz Complaints we have received absolutely no communication in the past month regarding the vehicle or a outcome.My last straw was when I called in and left on hold for 10 minutes while waiting to speak to Joyce from Mercedes Complaints.Every bit of communication was done from my end,not once did the dealership or the Complaints devision reach out to me as a client.Pathetic.