Yea basically the stock radio is worth about 20 bucks, and you know the story, "you get what you pay for", its a pity they include such a crap unit (and servos) with a RTR, but its to keep the cost down. Personally I would have liked to have paid a little more in the beginning and get something that would last a bit longer.
Cen should replace it for you free of charge IMO if you send it back to them.
The radio swap programme is a good offer, hopefully they start that again, IMO they should never have stopped it! Its a way that they can say "Hey look people, we F***ed up with this radio, but heres a way we can put it right without it actually costing us anything."

My 2 cents.