These are the 3 problems the brands, the vendors selling returns solutions and 3PLs need to look at solving together.
1. Returns with no sales order ID
Print your returns address on a shipping label with a barcode of the sales order ID on it so even if the customer pays for returns they'll use that label and when the parcel comes in you'll be able to match the return to order.
2. Incorrectly issuing refunds and adding inventory into Shopify by mistake
Automating refunds from the WMS / 3PL back into Shopify, reconciling what is returned with the returns platform. Why? Brands are using returns portals that aren't connected to the WMS or 3PL which means inventory can be added by mistake (don't forget to uncheck that box when you're doing 200 returns in a row) and refunds are being done manually.
If you throw in a simple returns solution like Clicksit which enables exchanges and you've got the perfect cocktail for someone to issue refunds on items that are out of stock whilst the exchange order sits there and then when products come in get allocated and before you know it....you've received your item free Mr Customer. Has this ever happened to you? Are you 100% sure you aren't making this mistake with your brand's returns flow?
If you're going to do exchanges and returns you need to design the end-to-end solution - Loop, Rebound, Zigzag...these are all great solutions for their part...you need to own the whole returns experience and only you are incentivized to make the whole thing work.
3. Lack of clarity of how returns work to reduce returns that just creates more chaos
If you don't want to 'encourage' returns start with a return form on the website for people to raise a ticket on Gorgias or Zendesk. Can do this with Airtable or Google Forms for no cost.
If you get a lot, create a pre-printed returns card and print the sales order ID on a label to affix to the card. Then the customer can take the instructions from the card and will have their ID when they come to do a return.
The reason I favour this solution is you should be removing A4 printers from your packaging benches. They're expensive, waste paper and it turns up crumpled...unless you use an envelope but that's all additional cost and most don't have the margins.