I am so sorry,  but you have waited far too long to receive any refund from eBay's 30 day MBG Money Back Guarantee policy and too long to claim from your payment provider too.
 
Never listen to seller's ' promises'  for resending a missing item, if it's not turning up in a few days you wait no longer and as this was one purchase and only part of the item received a case for item not as described needed to be opened citing.... Item Does not Match Description or Photos,  or ' Missing Parts'.  This gives the seller 3 days to fully refund you or send a label for the remaining item to be sent back.
 
If neither happens,  you escalate the case on day 4,  and eBay step in and force the refund.
 
eBay's MBG is written on every listing,  I've included a link for it below.  Please familiarise yourself with it,  as it could save you money in the future.
 
https://pages.ebay.co.uk/ebay-money-back-guarantee/
 
@lee-murrow