Asus Technology Pvt.ltd - ASUS Zenfone Same Problem Persist After Repairing

Sir, I bought an Asus Zenfone *Z last year. It worked fine for * months and in the month of June ****, i faced NO NETWORK, NO SIGNAL and NO SERVICE issue with my handset. Gave it to the ASUS Authorized service center for repair and again after * months the same repeating issue occurred. On further inquiry with the service center people, i came to know that there is a defect in the Asus Zenfone *Z series phones. this NO NETWORK , NO SIGNAL and NO SERVICE happening with most of the customers. For me along with the NO NETWORK, NO SIGNAL issue there was another problem with the main camera of this phone which center people are still working on it. I am worried what will happen when this product is OUT OF WARRANTY ( which is due in few days). I would really appreciate if ASUS people REFUND me the amount as this handset is full of defects and issues happened more often with me. As a proof , i am attaching the original bill along with my * recent visits to the authorized service center