Tired of the incorrect phone calls and sms'

I had my vehicle serviced at Eastvaal Toyota Potchefstroom in May this year, some how my name and number got linked to a lot of different profiles. Now I get a lot of sms' of how my vehicle is scheduled for service, then it is not even my vehicle. I get calls from Eastvaal Toyota to hear if I was happy with the service, and I explain to them they have my number on incorrectly and all they say is that they cannot take my number off, I have to phone Toyota SA to have it removed, now why do I have to use my airtime to correct their error. I have in the last 5 months received about 10 calls from their service consultants, and I have explained to every one of them this story, nothing has been done to correct it.