Unfain practice by Mercedese Benz Pietermaritzburg

Mercedese Benz in Pietermaritzburg has just told me that the maintanance plan will not cover the electrical wiring damage because they say its due to rats, i really fail to understand this and i feel that it is totally unfair to pay when my car has not reached 100 000km stipulated by the plan . Please assist me with this.