No, you cannot. Once a part has been installed, it is considered final sale. No refund, exchange or partial credit is available.
If the incorrect part is installed into a vehicle, it is now being subjected to mechanical and/or electrical stresses that it wasn't specifically designed to handle. This compromises the integrity of the part and puts the vehicle operator at risk of injury or death.
While you may not personally consider it to be a big deal, would you be happy purchasing a "new" vehicle part that had been clearly installed before? Do you know how much stress they were put under, or how they were handled? Would you trust your life to a part that may already be damaged?
If you are ever unsure that you are ordering the correct part, review the manufacturer's website, contact the manufacturer directly or check your vehicle owner's manual.