Poor service from Merc Service advisors At Centurion Mercedes

I have purchase my vehicle from this branch 5 years ago with the 5y maint motorplan.I have been battling after 4 requests for merc centurion to contact me with a quote for options available to continuie with a maint plan. To date and after complaining to do a follow up after serviced, no luck I made a service booking 2 weeks ago and when i took it in for service this morning they could not find my booking? Question, I have been a Merc owner for more than 30 years.Why should i bother replacing it with a R1M plus if Merc dont even bother to send me a quote for extention on my motorplan!! I will contact other motor plan service plan providers.Maybe they will be intetested?