I'm also sorry your template designer is not helping you out. We have some new features in Auctiva that will allow to bulk apply a template to saved listings. In the saved listing page, you can select up to 250 listings by settings the "Items/Page" dropdown in the upper right to 250, then click the checkbox next to the post button on the left. Once the listings you want to update are selected (I'd start with a couple just to make sure you like the new template you selected), click the "Advanced Edit" button and in the dialog window select "Listing Template" for the field. At this point click the "Select Template" box and select one of the new active-content free, mobile-responsive templates and continue.
Once you complete this, you can bulk repost the listing it will have the updated template, removing all of the horrible listings that other designer left you with.