Requesting Refund from Cash Crusaders Franchising Belhar

Good day My name is Vuyo Ngoma, I am lodging a formal complaint regarding Cash Crusaders at Belhar. I purchased a DSTV HD decoder on January 30th and it never worked . I returned it on February 3rd, within 7 days of purchase and despite assurances. I went to the store on the February 7th to check how far is my repairs as I was promised that they will get back to me then again on February 10th I went there and I was told that the manager is not available , today I went to the store and I was told that I must wait for 21 days .he store manager still refuses to refund .now require your urgent intervention to resolve this and secure my money back.