My husband bought the mixer for me as a Christmas present back in October. I was very excited to use the mixer and especially the flex edge beater for xmas cookie batters. I couldn't even use this beater because as soon  I put it on the beater shaft it was making this horrible noise. The other beaters do not make the noise and was able to use them but now I noticed the flat beater has some of the white enamel coming off...Ugh! Such an expensive item to have this happen. Please advise!!