After the CS = LOW, MSB goes out, then you will give the next pulse, at the Falling Edge of the next pulse, you will get BIT6 (MSB is BIT7 and LSB is BIT0). Then you will repeat this until clock 7, at clock 7's falling edge, you wwill receive the LSB or BIT 0, on your 8th clock's falling edge, you must put CS = HIGH, meaning your ADC will be disabled now, then you can put CS to LOW again and start the same method above.
I hope you are not getting errors due to a bug on your software.