Okay. Putting together the pieces you have provided so far... Making some assumptions . . .
You have an 'older' computer system (would you mind sharing the make & model?) Somehow (would you mind sharing how? Upgrade? If so, from what OS?) the system ended up with Windows 8 or 8.1 (which one? can make a difference.) installed on it originally and activated (how did you get it and how was it activated originally? How did you get your product key?) Something happened and you had to try to re-install. You (many assumptions here) decided to do a clean install of Windows 8.1 and when you attempted to activate, it failed. You then tried the instructions to activate by phone and the automated method failed. You then chose to speak to an operator and even then, the activation failed.
So, how much of that is accurate? Can/will you fill in some of the blanks to the story so we can figure out more details of where things could be going awry?