Please help! Major problem with app

Hello,
I have been having problems with my Galaxy S4 for a while now. O2 have said it is a software fault or something is stuck in the earpiece but as the phone is out of warranty I cant afford to get it fixed. I have tried a factory reset and also tried cleaning the earpiece with no luck.
The problem is the phone constantly flickers between thinking the earphones are connected and then not connected. This happens 24/7. I installed the SoundAboutPro app and was able to force media audio to the speaker which fixed the problem. But for a week or two now an error message constantly comes on my screen saying 'check your media audio settings as they may conflict with a headset being plugged in'.
This error messags comes up about 12 times per minute all day which means when im typing the part of the keyboard which is covered by the error message cant be used till it dissapears. It also results in the music playing then paused then playing then paused etc etc. Also during phonecalls the phone goes to speaker then off speaker etc etc. It is doing my head in! The only way to stop the error message coming up is by putting media to wired headphones in the app but this means any music or phone calls or text messages I can not hear.
Is there anyone who can help me and advise how to force this error message to stop appearing and route the media audio to speaker permanently? Please!