I presume you mean that your current membership doesn't expire for another couple of days?
In that case the new membership will stack and kick in when the current one expires.
It will not start immediately.
All memberships always run their full monthly course.
If you have used up your current membership allowances (e.g. data) then you may need to look at buying an add-on to tide you over until the current membership expires and the new one kicks in.
http://www.48months.ie/membership-plans/add-ons
Your online account clarifies the details of current and stacked memberships in the "Membership Planner" section.
https://www.48months.ie/my-48
Hope this helps.
