You can fix it in just 2 steps below:

Step I:
Enter your meter number and NIN to link your NIN to your prepaid meter in under 2 minutes using this link-
https://smartkyc.ikejaelectric.com/

(Nb: you don't need to be the landlord to link your NIN to your meter, the system will ask if you are the landlord, just click No).

Step II:
After linking your prepaid meter to your NIN, go ahead and make an electricity purchase on simply buy units from your bank app or Anywhere else. You will receive 2 sets of tokens separate from the light units tokens you bought. These 2 tokens are called kct1 and kct2.

Enter the 1st set of token into your prepaid meter and press enter. Enter the 2nd set of token into your prepaid meter and press enter again. Your meter will migrate successfully.

Step III
You can now enter your unit tokens to load successfully and wil not see a rejected message when next you load.

Most common problem
If you have linked your NIN to your prepaid meter and you have made a new electricity unit purchase but did not receive your ktc tokens or only received incomplete tokens, then click the link below and enter your meter number to receive your two sets of kcts:
www.Ikejaelectric.com/kctcheck

#Enjoy

If you have more queries, share them here on contact your disco customer support

I want to really appreciate you Murzmann.
This information was really helpful. While I was busy looking for someone to assist, I got this info and it really worked very fast.
Thank you