Postage discrepancies

[ivycat1!]

I have bought many dresses from Ebay & the postage each time is around £3.50 first class. I bought a dress recently and queried the £5.75 first class postage. I was told Ebay had said that was correct The dress came today & the amount on the post office label is £3.55, the same as Ive always paid. There has been no offer of reimbursement from the seller & i dont expect I will get the extra i paid back from her. Is there any way i can claim this back?

[pixiesen2012]

no, you can't claim it back,

sellers state a P&P amount to get the item safely delivered to your door, it isn't just the cost of the stamp

you agreed to pay this price when you bought the item