Do you know how to SSH into the pi or using the console with ctrl+alt+f1 ?
If so, you can play around with the overscan of the TV until you get your perfect fit.
for example, the /boot/config.txt file has these to play with, try these negative numbers to see if it makes it better, you can continue with larger negative numbers, on one of my TVs I had to use -32 as the left and right one for it to fit perfectly.
Good luck, let me know how it goes.
overscan_left=-20
overscan_right=-20
overscan_top=-10
overscan_bottom=-10