You need to read the T&C very carefully with regards to 'pay at hotel' options.
For mydealsandcoupons.com and booking.com you will get 0 cashback for 'pay at hotel'.
For different cashback sites and hotels.com, I have successfully received cashback also for 'pay at hotel'. Cashback rates and T&C are constantly changing so verify before each time.
Where do you find the T&Cs for topcashback and mydealsand coupons for booking?