ECU unstable and wrong diagnosis from M force

Dear SYM riders , already been in the service centre for four times to check what is wrong with my sym 250 i evo idling , now thay tell me is the head gasket to be changed, while I have no coolant lost , no oil spilling , the engine is prefectly dry .
I feel here thre is something wrong with the peoples in M force , just looking for escape route to say is not the quality of the scooter which is very poor. I am not simply going to do it as thay say , it is need to have a better investigation and diagnosis of the real problem, my opinion is an electronic or setting problem of the ECU.
Indeed , my scooter has only 25 000 Km count till now , it seems very strange to have to do the top overhaull at such low milleage , or there is a serious quality issue in the SYM engines.
I will get at the bottom of it and let you then know waht is the real reason why our scooter is so fragile and poor on reliability.
RGDS
Spartacus