Walmart does not sell parts for air conditioners. However, the store does sell some air conditioning installation accessories. It also sells side panels and specialty coolers for air conditioners.
If you have purchased an air conditioner from Walmart, you should contact its manufacturer to find out about servicing options. If you have a warranty for the air conditioner, you should refer to its terms and conditions. You can find out from Walmart any additional terms to service the machine.
If you did not purchase the air conditioner from Walmart, you should contact its manufacturer to find parts or a repair facility.