returns 14 days or 20 days?

[tkni5451]

I have only previously had 2 returns, but having sold a bike, which the buyer received inside the promised delivery time, he found in reassembling it, (Boxed for transport) there is unfortunately a small adjustment required in this case, which takes about 10 mins but he did not want to do.   The buyer claims it will cost him £200  to get done ??? (Bike was £125)  

As I was reluctant to pay £200 for a 10 minute job, he subsequently opened a case and I agreed to take it back crediting postage both ways.                    (This was 25th June)  

Under ebay How to return an item, it states that  - you must return the item – in the same condition as you received it within 14 calendar days of requesting the return. However eBay have given him until 15th July to return it. Which is 20 days He states that he will dispatch on or after the  11th July and yet ebay tell me that if I sent him my own label (I used their service) I only had until the 4th July to do it.

I have today asked eBay why the seller has been given 20 days and apart from it being a malicious action waiting 15 or 16 before dispatch, is he allowed to do this when I was supposed to agree by 4th July

Ebay tell me that the help page on their site has errors but their current policy is what counts, NOT WHAT THEY PUBLISH !!

I have asked to escalate my complaint but I am told that advisers have absolute and final authority. Where does one escalate a complaint ?