Here is my understanding of your circumstances as described above & my thoughts on it:
the supplied tracker number:
-->is for a delivery item signed for with an unknown signature for it, delivery is NOT from your local delivery sorting office..
--->Royal Mail are initially 'confused' by the delivery tracker number detail,
--->the seller claims to you that he contacted Royal Mail over this delivery/whereabouts issue (Royal Mail would have referenced this delivery on their systems & logged this contact & nature of it from the seller on their CRM systems)...
--->seller has NOT been able to give you a valid claim/reference number for this 'lost in delivery' claim he said he will be making for the item ....
---->Royal Mail now confirm to you that no parcel as described by the seller was ever delivered to your address & NOT from a regional delivery office & Royal Mail also confirm that there is NO claim made against this item to them by the seller as described/claimed to you by the seller.....
CORE ISSUES: 'Seller used RM next day 1pm'--->
I gave the seller a few days then asked if he has posted it, to which he replied yes and gave me a tracking number. All good… However when I checked the tracking number it said it had been delivered'...
-->so if it was a next day delivery or its terms of delivery were to have been of this nature, judging from the outset of the delivery terms before you won this auction, why did you therefore wait for a few days before the contacting seller for posting details ???
--->
'Had a parcel delivered on the same day from Ebay. Item was similar in size & weight (tracking said local PO, known signature)'.<----this was a successful delivery right, utilising the same delivery firm & terms of delivery as the first phantom delivery, for another similar ebay auction you won ???
---->
Now I’ve done a little research, & it seems Ebay generally find in the sellers favour due to the item being tracked & signed for (apparently)'....what do you mean by this, please clarify....??? At this moment in time, you have lost a small pot of money, so really are you not supposed to be engaging ebay/paypal under the buyer/seller protection scheme to remedy this issue having failed to have any meaningful engagement with the seller who patently seems vague & ambigous to you & it would seems he has lied to you about his contact with Royal Mail as they don't know about any of the sellers contact with them as the seller claims /possiby consider contacting the local police to forward a crime reference number to paypal/ebay to progress this (from my previous experience).....
--->the item tracker number supplied by the seller supposedly for your item.....could be a dud tracker number supplied for a previous delivery item totally
unrelated to your own order but you have been decieved by the seller into thinking it is for your item---->>decieved for the purposes of FRAUD; this situation gives the seller an option of making an item 'lost' claim through the
ebay/buyer seller protection scheme & reclaiming the value of the 'lost' item.....everything you've said about your seller's conduct ranks of
>>>FRAUD<<< on your seller's part & you will have a job to substantiate/provide proof to paypal that you have NOT recieved the item, you are likey to need to file a 'fraud police report to get a crime reference number before paypal will action this & review & give their verdict on it.....
ENGAGE THE BUYER/SELLER CLAIM PROCESS FOR BOTH PAYPAL & EBAY, THOUGH EBAY MAY LET PAYPAL TAKE THE LEAD HERE.
I agree with
GreenBean sentiment about you providing more details via PM to him to determine the veracity of the information you've provided on here before he decides to assist you further.
BTW, I would also advise you to use the 'advanced' search feature on ebay to locate the sellers contact details for reference.