Packlink are simply a courier booking service like SHUTL offered as an option by eBay.....you do not have to use them......I never have
Why add another tier of administration to a sale....one more place for something to go wrong....use Royal Mail or book direct with the courier
Packlink are not eBay & eBay are not Packlink.....so you must ensure you read the T&C of using the Packlink servce thoroughly.....and you contact Packlink if things go wrong.....but I doubt most of the things yyou sell would be insured through Packlink
As also pointed out your more serious issue is that you are trading as an unregistered buusiness seller leaving you guilty of fee avoidance, VAT avoidance & illegal T&C in not accepting returns......you need to change your registration status to ensure you comply with eBay T&C and your legal responsibilities as soon as possible
