Windshield Wiper/washer problems of the 2004 Chevrolet Impala

Incident description = I purchased rain-x wiper at walmart for my 2004 Impala vehicle. It cost $17. 99+ and was a 22-inch model. A week or so later I ran into a heavy downpour while driving west on I-40 from memphis to little rock. The wiper portion of blade assembly began to work its way out of the end of the holder and quickly reached about 5 to 6 inches outside the holder. The rubber began to whip around and I had to pull off the highway to put the rubber part back in place. This happened 3 more times before I had to stop and search out a Mini-mart where I could buy a roll of electrical tape to tape the rubber end tightly enough so it would stop flying out of the holder.