Tire balancing isn't rocket science

wow - I have been dealing with the exact same problem. I bought a set of tires for my truck recently and I had to go back 4 f-ing times (hey, thanks for wasting my time guys!) before they admitted that the tire itself was bad and would put a new one on.. the shake was so bad at 45-50 you could make your voice practically sound like you were yelling into a fan! I went back because I wasn't letting them get away with it - but they did lose a customer in the process.. I am convinced they were trying to sluff off a blem on me..