Why do i keep getting disconnected from my internet? (aol)?

i have aol broardband silver nd it was alwayz have been a good internet service ovr the laast 4 years til october. i went away to blackpool came back a week aftr and the internet keeps disconnectin me ever since. i have complained it too aol 3 times b ut they keep messing around with my router settings and also reset my router twice but the problem comes back. they dno wa it could be. do you fink it could be my phone line which is BT ? would it b worth ringing them up? because the middle green light on my router keeps turning yellow and starts flashing then turns green then turns yellow again blinking now and then which disconnects me from the internet any advice would be greatful and also i have no interferrence from other sources.