Internet works when it wants

I upgraded my Telkom adsl on a 2 year contract and for the past 2 months, my adsl just goes off and comes on at random times. If I try a username and password from another ISP, the internet works fine.<br> When I change back to Telkom username and password, it doesn't work.<br> After half an hour or an hour, it suddenly starts working again and does the same thing later that day or the next day.<br> I do nothing to cause the internet to go off. No one touches anything and it comes on again.<br> To call Telkom helpline, you need 5 hours spare to hold on as no one will answer your call.<br> An agent did reset the port a couple weeks ago but problem started again.<br> I have 3GB of data left being the last day of the month and now can't use it because it has been off for 2 hours now.<br> This can't go on.<br> I can't be paying for something if I can't use it.