MTN just dropped a message to my inbox.
The MTN data deals are pretty interesting.. You get extra free data when you subscribe to the plans below.
MTN DATA DEALS! Enjoy
4.5GB + 4.5GB FREE N2000 (30days)
12GB + 12GB FREE N3500 (30days).
Dial *131*110# or *131*107. Offer available till 21-Jan-22
As you see, you receive 4.5gb free extra when you subscribe to a 4.5gb plan at N2000.
And that is 9gb for N2000 only, MTN is also giving 12gb free when you subscribe for a 12gb data plan at N3500, i.e 24gb for N3500 only.
Offers available till 21 January, and validity is 30 days.