Hi hossein,
The major question is why Left Wing Tank Quantity at detination is the same as we start from departure point. 3300 kg remains all the way on the left tank, no change, with consumption of Eng#1
If "Total fuel on board 7600 kg
(3300kg each wing tank with NO IMBALANCE)"
Then you must have started with 1,000 kgs in centre tank, which was used once the Flaps/Slats were set to zero. Therefore you only used fuel from the Left Tank during Take off and early Climb (say 500 kgs).
You had at one stage 3440 Kgs in Left Tank (2730+710) which shows that the NRV (Non Return Valve) to the Left Tank was leaking slightly and that the pump output from the RHS pump was greater than the pump pressure of either of the two LHS pumps.
That is why all fuel plumbings have X feed valves etc. to prevent fuel migration from one side to the other. If you had turned both pumps off in the RHS, then only the fuel from the LHS would have been used.