Goldwagen warranty not honoured

I purchased a voltage regulator from Goldwagen Mokopane branch and installed the part. It was working perfectly, charging the battery at the correct voltage as it should, but as soon as you switch the car off it had a current drain of 5A on the battery which caused the car to be jump started every morning. I took the car to the mokopane branch and wanted to show them what the problem is with the regulator in place. they just told me that the company policy was for me to take it out and they will send it back and after 2 weeks I can come and hear what the verdict is. I got it back after 2 weeks with a report that the voltage regulator is fine and are charging at the correct voltage. THATS WHAT I TOLD THEM in the beginning. The regulator works fine, but it drains the battery when switched off. they refuse to refund me. If they had listen and took a little more pride in their work when I took the car there they would have known what the problem is and would have written the correct customer complaint on the form. I in the meantime bought another one from Autozone for half the price and my problems was on an end immedialtely