Sounds like the gyro sense is reversed.

Do the following checks.

Make sure the tail is spinning the correct direction, that is, counter clockwise looking at the right side of the helicopter (nose left, tail right)

Give right rudder, make sure the tail blades change pitch so as to push the tail to the left. If thats wrong reverse the rudder channel.
Pick up the heli and turn the nose left, the tail blades should do the same thing as above, if thats backwards, reverse the nor/rev switch on the gyro.