poor customer service n a ***** return policy

On the 25th of October 2017 I purchased a brand new starter motor from the goldwagen in Kenilworth as my regular goldwagen branch in Montague was out of stock , a few days went by (approx. 5) and I had to return the starter due to the fact that it was no longer needed (mind you it's still in the original packaging, which was damaged comming from the back of the store) as I am closest to the the Montague branch I started there and was adv. by the guys there that I needed to return it to Kenilworth branch of which I understood. Got to the Kenilworth branch n spoke to Don the branch manger at the store , Don the branch manger without evan introducing himself grab my POP(proof of purchase) n took a quick look at it and interrupted me in the middle of my sentence and said very in a very unfriendly tone ,that I cannot return the starter as it is an electronical product and it's past the 5 day return period (which was news to me because as the original sales lady shakirah did not explain this to me on the day of purchase ) , I adv. Don the branch manager that I was not aware of this policy as it was not explained to after a few minutes of back and forth , he said I was welcome to call the Head office and let them explain the returns policy, I then requested for the number of the area manager and then he quickly took the phone called himself after half an hour waiting for Don the manager to pass me the so that I may have a convo with the area manager , Don the manger came back and said that he will only credit me the motor if I spend to the same value as the starter , which I didn't agree with as I didn't even use the starter he the said he will credit me monies but 20% less than the original price (which was R1335.00) , I accepted the deal as I was already tired of being in the store due to the lack of customer service and unprofessionalism of the place , my problem is 1. Why is your return policy on electronic parts 5 days? 2. Why must I pay a 20% handling fee when I return parts? 3. I would like to know the answer to the above questions and ask what are going to do as I don't think I will be using your business again due to the lack of professionalism at your branchs.