Power Beats not Charging

Having a problem with my PowerBeats Pro not charging and have corrosion on the charging points. I would use them and the next day or so later need to use them again and either the left or right ear bud would be dead after taking them out of the case. This was my first set and and Apple replaced them. The second set had the same problem after about 6 months. This pair was sent into get fix and I was told I damaged them and I needed to pay to get them repaired. Problem I had was they were not damaged when I turned them in. They sent me a 3d set (bottom photo). Now about 6 months after I received that replacement noticed more corrosion on the new set. I just got off the phone with support and the fix was to just clean them. I have tried that with the first two set and it did not fix the problem. I love the sound of the Beats however I am fed-up with the charging problem.

Has anyone else have this problem? If so how was it fixed?