Default Goods sold to Customers

I bought a car tape for R2600 on 2015/11/12 and I took for installation & hardly 3 weeks down the line the tape just went off by itself while playing & I was driving to the wedding on Saterday 2015/12/11. Sunday 2015/12/12 I took the take back to the installers to check n it was confirmed that the problem is with the tape as they put back my old tape which just played fine. I went back to the store & the guy assisting me on their customer services was just not helpfull & rude I asked to see a store manager I received the very same attitude. I asked for a new tape as I cannot go without music in my car as I travel a lot & is Christmas time they refused & said I must wait for 21 days to get the tape fixes & the firm is closing for christmas so I will get it wen dey open. For heaven sake I paid lot of money as I was expecting for the quality of the tape to be exeptional & da next thing I get is such a servide & treatment. I cannot believe that u spent 2600 on a car tape & few weeks later it goes off because is a default goods & u are told to wait I drive a car with a hole in front of me but i just spent a fortune in a store that cannot refund you or give you another tape after 3 wee