Changed Prices of membership – Not updating for renewing members


We have many set date range memberships on the site with different access levels. They were originally set up for access between Jan16 > Dec16 but we have recently changed the dates to Nov16>Dec17 so people are able to ‘renew’ the membership by purchasing again for a new date range.

We have also recently updated the prices of the memberships but I have noticed a note that states ‘this will only effect new invoices’ I am trying to renew a membership at the moment and it is showing the old price – however if I choose a new membership to sign up for the prices seem correct. Will this happen if members were signed up for the membership they are renewing before the prices changed? The prices do seem to be correct for new members if I create a new account. If this is the case, why is it generating the old price when it should be a new invoice for the next year? After the original membership date (Dec 16) will the prices up date?

Is there anyway to resolve this please?