@Ayodee what you meant by plan didn't activate?
Are you new activated or exsiting customers?
If existing customer and just made a plan change, Please login My Account once again to Incognito mode and you should see the new plan (the My Account has some cache problem)
If you are newly activated, You cannot login to My Account anymore?
or the sim card does not work?
If it is sim card issue, first, what band and model is your phone
Next, any error showing on the phone status? No sim? No network? Sim not provisioned?
do you have another phone to test it? or at least reseat the sim card once more time
give me more info and tell us what you tried
