Admob Problem

I've been having problems with admob ads not showing.I have an app builder with a whitehat version of serbiancms.
The ads didn't show in that so I joined builderall on a trial and again no ads.
The plugin for Cordova also stopped showing ads.


I joined Appyet again no ads, a lot of talk in their forum saying ads haven't worked since January.

After giving up on the support of the various I looked to youtube .most of the videos with anything to do with apps is in Hindi.

But I found one and installed an app called Apk editor, which basically resigned the apk with its own Version of the key.
And straight away after reinstalling the apk that I had just resigned the ads are showing.

The plugin for Cordova also stopped showing ads.

Is there anybody else having the same problem or can anybody offer some advice