Faulty router.... AGAIN!!!!

In April 2014 I started a contract with Vodacom for a WiFi router, 2GB per month for R129. In November 2014 the router stopped working, saying that it is not in range even though it is charged full and right next to my smartphone. I gave the router in for repairs and received an exchange unit a week later. At the end of December 2014 the same thing happened, I gave it in for repairs in January 2015 and received an exchange unit in May 2015. This unit however, did not word at all. I gave it in and received another exchange unit a week later. The router worked for 3 weeks and in June it showed not in range again. I gave the router in for repairs AGAIN and received a new exchange unit AGAIN 2 weeks later. Now, after working for 2 weeks, the router again shows not in range. This absolutely ridiculous! This is the fifth new router of the same model which has the exact same problem. I have to buy mobile data extra for my smartphone and I still have to pay the R129 monthly for nothing.