campaigns under performing after double serving!

[SEMblahblah]

I had this campaign (say X) running..performing pretty well..meeting the required targets of clicks, spend, etc.
Then I happened to add another campaign (say Y) in the same account, which used quite a lot of keywords used by the previous campaign which was still running.
Now, since google, at a time, serves only one ad for a particular k/w from one account, both my campns started suffering. I opted in for ad scheduling so that both campns run at different times!did not help!even the keywords involving brand names in the newer campaign(Y) went inactive...neither did the performance of the 1st campn(X) get back to normal.
Now, I've paused the new campn(Y) for other reasons..it has to go back live again sometime soon. Was expecting the older campn(X) to perform as it earlier used to..hasn't happened!
Why so?
Is it still suffering from the effects of double serving or wht?

[SEMblahblah]

now the first campaign has stopped running. Yet, the second campaign is suffering with poor QS even for the brand names and many inactive keywords(have previously run many campns for the same, and have never experienced this).
Have been contacting google help for over 2 weeks now...they say they'll get back..but it never happens!
Anyone with a solution to this?

[PPC Consultant]

I have seen instances where if you lower the CPC and then push it back up, it will not give you the same position. They almost penalize you for trying to go back lower...