Still not getting what I am paying for!

I am paying for a 2mb/s ADSL line for the first week every thing went well I was happy with my line , my ADSL line got slower and slower I phoned Telkom 2 week ago they only reset my port then it was working for 2 days , every time i call them they reset my port and then it works for two days then i need to phone them again to reset , at this point the reset does not work any more , so what I do not understand should they not have already told me there is something ells wrong with my line , why am I paying for a 2mb ADSL line and only receiving 0.22mb/s?