Sorry to hear about your issue. You selected "Change Plan", and then "Build My Own Plan", and in Step 2 it defaults to "No Talk". I suggest you build a plan again with the talk option, and for next month just ADDON whatever you need, instead of build...
Was each voucher less than the amount required for the plan? It's very well possible now that your plan is active, you can add in each voucher and that value will be used for next months renewal. Let us know if that is the case. Good luck!