QC Ultra earbuds, left earbud making constant noise

Hello,

I purchased the QC Ultra earbuds last month but I have had them replaced 2 times because the left earbud made constant annoying noises. Now the third one again has the same problem. I read on some forums that other people have the same problem and some don't so I just wanted to ask is there a fix for this yet and should I keep trying to get them replaced until I get ones which are fine? I really like the anc and the sound of the buds but I am getting real tired of the faulty left earbud. Thanks for any advice.