Dismal Service from Mark White Nissan

Dismal service from Mark White Nissan Fourways - my car went for a major service at the end of last year and I had to go in twice thereafter for further issues that were not detected or corrected during the service (one of which was a fault on the fan). Today I had to return because of a faulty fan AGAIN and I'm being told that the part may or may not be under warrantee and AGAIN I will be without a car indefinitely until this issue is fixed. Never in my life again will I buy a Nissan especially if this is the after sales service experienced! Shocking!