Motherboard problem

I have a l502x.my motherboard have broke down and I called dell Turkey partner (serjoe) and ordered a motherboard but this motherboard was defect.and they(serjoe) sent me a new motherboard.and this motherboard was also defect and then they are going to sent a new motherboard and now I am waiting for new motherboard

I am not assemble this motherboards on my laptop by myself. This situation imposed my economy.
this situation wasted my time a lot.

I want a durable motherboard.no longer,defect motherboard isn't send me and ı want to supply my loss.....