Royal Mail Nightmare, or Is it Ebay's Fault? Please help

[cracklingdeals]

Hi peole, I m a fairly new seller, I sell around 500 items per month,  Last month and this month I m experencing some huge issues with ebay and Royal Mail, 90% of my parcels I send with Royal Mail 2nd class,been going ok untill last month, I was RECORDED 20 LATE DELIVERY DEFECTS.  I tried to appeal them but they all god declined, the thing is that Ebay says I dispatched item on 12th of May and it was Delivered ON 12TH OF MAY, but I have all the postage receipts saying that I dispatched my item on 6th of May.  I called Royal Mail about it, they think its an issue with scanning. Also, how damaging is Late delivery defects on the account? as due to this issue they are quikly increasing. I contacted ebay about it, all they can say ''we understamd we are sorry'' but no action is being taken, I was given a link to upload all the evidence, But again no one wants to work and go through all of this. Ebay, charges me 1000£ every month, for promotional and final value sales, but seems all they care about is taking my money, when it comes to real help, I cant get any.  Where should I go next from here? I m honestlym feeling helpless and getting to the point of stopping selling and just closing my account, as so far, Ebay makes motre money of my sales, than I do, the fees they harge are HUGE and the help I get is NOTHING. 

Thank you for any ideas