Push cert renewal

Hi guys when trying to renew (expires in 5 days) i follow the instructions except it says you need to renew in order to renew the expiring cert and only gives a choice of $499 we are on the starter plan for a few devices which we paid $149 i think for - where is this option and if not how can i renew without paying for us what is $600 we dont have ! Hope everyone is covid free and safe !