Dachshund Rescue WooCommerce Shop - Configure shipping rates

Dachshund Rescue Australia Inc is a group of volunteers devoted to the rescue, rehabilitation and rehoming of dachshunds in need. Charity number CFN/23452 Registered by the Australian Charities and Not-for-profits commission -------------------------------------------------------------------------------------------------------------- A shop has been developed to sell merchandise to raise funds here: [login to view URL] Unfortunately the previous developer was not able to configure the shipping so that items were combined on checkout and buyers charged correctly. We have purchased the WooCommerce Aus Post plugin and tried setting up boxes within this but it doesn't seem to be adding up the product dimensions/weights correctly. e.g the stickers can be sent in an envelope which costs 70c to send but on checkout, the shipping costs are calculated at $4.65? An overview of the requirements and problem is below: Due to their size, the balls and bags (cat 1) will not fit in a letterbox so need to be sent via parcel. Postage cost: $7.20+$1 handling/packing The stickers and id tags (cat 2) can all fit in a standard envelope as they are small enough to fit in a letterbox. Postage cost: 70c + $1 handling/packing We need a solution which allows the follow: - up to 10 cat 2 items to be send in 1 standard envelope (before the envelope gets too thick) - if a ball or bag is selected, parcel postage rates apply - cat 2 items can be added to a cat 1 order with total cost dependant on weight. i.e if someone orders 1 ball, 10 stickers, 10 id tags could be added to the parcel for the same postage costs. -- If the above makes sense and you have experience insetting up woo commerce shops with combined shipping, please bid. Any questions, please do not hesitate to contact me. We need this completed ASAP Thanks