I am sorry to hear that have had issues with processor model i7 4700MQ.
I have checked the picture attached and indeed shows 2 cores and 4 threads.
At this stage, please check for any BIOS settings that may have disabled CPU cores or try updating BIOS of the computer here:
By updating computer BIOS you may get Turbo boost running on the computer. If you need further assistance I recommend engaging through Lenovo's Technical support at: