So, the rear 'arms' of the bike have bent in causing your brakes to rub. The most logical question is, 'well, how f***ing thin is your wheel?' And the most obvious remedy is spacing. If you have put spacers on your rear axle and the brake is still rubbing, the next step would be to make sure the TPA is wound out. (The red knob on your brake levers, wind them to the minus.(Just telling you in case you didn't know)) If your brakes are still rubbing, time to set them up again. Place them as far away as possible and make sure you do the bolts on the brake clamps up and make sure you do it tight as they will move out of position if done pussy handedly. If your brake still rubs, revert back to step one and add more spacers.