Cell C - Data Bundle Extension

Hello,

With reference to Cell C having taken action by allowing customers to extend data bundle expiration dates, by purchasing additional data:

Please can you answer these questions for me:

1) Is it possible to extend my existing "Cell C 100 GIGA" 12 month prepaid data bundle that expires on the 30th of January 2018, by purchasing more data?

If it is possible, then I assume that I must login to my Cell C Account at this url (https://www.cellc.co.za/cellc/get-databundles), and choose one of the "recharge data bundle" options.

There are two options:

a) 30 day option.
If I select anything from 30MB to 30GB, then will my existing "Cell C 100 GIGA" 12 month prepaid data bundle balance, be extended by 30 days?

b) 365 day option.
If I select "SMARTDATA ONCE OFF 100GB @ R1599", then will my existing "Cell C 100 GIGA" 12 month prepaid data bundle balance, be extended by 365 days?

2) When I login to My Cell C account at their website, it says that my data will expire on 30-01-2018. Does this mean that I can still use my data on the 30th until 23:59 or will the data only be valid until 23:59 on the 29th of January 2018?

I would be most appreciative for your answers.

Thank you.