Macbook Pro Fan and Battery issues since Day 1

I bought my Macbook Pro in July 2019, and it has one of the best specs, however from day 1, it is quite unstable and often the battery is draining and the fan is running. Apple support has spent possibly 5-6 hours, I have had to do an entire clean up of the hard disk etc. It is frustrating that 6-months on, I have still a sub-optimal laptop, that i cannot use when I am out (without a power cord). Any one else suffering from similar issues or how to resolve? I have done OS reinstall etc. Had to reinstate everything, and like every transfer it takes ages, but it is highly frustrating especially since this is the highest value product i have ever bought from Apple...