It is IMPOSSIBLE for a humbucker to be the same volume in full and in split/single coil mode......physics dictates this cannot be true, you have different resistance and outputs.....
Fender has warranty REPAIR centers, but any Fender dealer can return a guitar due to a defect.....
Fender has a 2 year warranty covering anything faulty - you can get a FULL refund even outside the return window......or have it repaired for free at an AUTHORIZED repair center....
You have to contact Fender consumer relations yourself DIRECTLY..... [email protected] with proof of purchase, photos of your receipt of purchase etc if possible, description of the problem.....