Daylight ******* - Goldwagen Vereeniging

I bought a part and it turned out to be incorrect . Upon returning it within 7days for a refund ,I was told i need to pay a handling of 15%. What handling fee because this is over counter sale , what handling fee as that was not stipulated to me and on their slip,there are no T & C's s. The part was not even tempered with ,it was still intact in it package . This is Goldwagen Vereeniging ,unfair treatment . Unhappy Customer .