Can i possibly retrieve some numbers i backed up online a few years ago, if so, how do i go about it

Hi Wole, you can login to MTN backup online portal to check if the numbers are still there you can contact their customer care for them to check for you.
You can use this link to access their portal
 You can access or restore your MTN Back-Up details through the self-care interface via https://mtnnigeria.weballynis.gemalto.com/CloudBackup/ind... then, you will need to login using the information received by SMS.
 If you did not receive an SMS with your login and password, you can get access through the Self-Care interface by:
a. Clicking on “Do not have an account yet” if you have never received the access information before
b. Clicking on “Forgot your Password” if you received it and then forgot it