After ordering and installing an incorrect blower ...

After ordering and installing an incorrect blower motor resistor, Rock Auto refuses to refund my money because it was installed. This part is a simple under the dash installment requiring only two screws and was installed only a few minutes before realizing it was an incorrect resistor. There is NO customer service with this company so buyer beware. I am unjustly stuck with a part I can"t use. I'll NEVER use Rock Auto again. Screw me once shame on me........