Stay or Go

I work for a Global MNC as a system administrator in the IS dept performing server support for around 2 yrs.

During my time away from office like on medical leave, I was unable to rest as the helpdesk staff contact me instead of my colleagues who is in office. Other reasons is that I m technically compentent and never make the point to refused anyone and also I used to continue perforn my working on medical leave.

My colleague and myself are suppose to cover each other when either one of us re away from the office. But for the past yr, I had been performing her tasks thus spending more time working and spend another 40 hrs on top of the standard 44 hours required by the my country labour laws. Also we had disputes due to different working styles .

I had made known to the line manager but to avail, it still remain the same and since then I had decided not to handle her tasks unless my colleague is not in around. Finally I had my own personal time after stop performing her tasks but this resultant me as unapproachable and unhelpful.

This had resultant me to look for a jobs elsewhere. But to no avail, I did not manage to get through any phone interview as I had problems pronouncing numerous words even though I had no problems with written English.

? What can I do stop as it had affecting my life? Stay or Leave?
? I had try to say No but sometimes but it give perception of being unhelpful and somehow being left out how?
? Also being helpful can also lead to be busybody?
? It had taken a toll on my health but I like what I am doing and like working in the company. Should I move on or stay?
? My effort is not recognized when I try to fulfill the service level agreement to the users but in the end being taken advantage.
? Two years working with someone that is stubborn and also working even on medical leave as it is a day to day operation not a urgency.