A new membership does not start immediately if you have a current membership in place that has not yet expired.
In this case the new membership stacks to kick in when the current membership expires.
Check your online account to see if this is the case here.
What does it say about your current membership and expiry date?
Does it list a "next" membership and start date?
If you have used up your current membership allowances then you need to buy add-ons and not a new membership.
If the membership has stacked then you have not lost/wasted any money as the membership will eventually kick in when the current one expires.
Hope this helps.