I left my computer to be replaced with the motherb...

I left my computer to be replaced with the motherboard. They did the service and installed Windows. Soon after my computer started to crash and I took the PC there again. They did not solve and if you want to give me a diagnosis so I know what to do with the problem. I took it to another technician and he gave me that the memory slots had not been placed in the correct place. That is, total neglect of this company. I do not indicate !!!!!