Scammed, but cant start money back process

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Hi, i recently bought a ps4 for over £200, unfortunatly it has become apparent that it was a scam due to the sudden influx of bad feedback the seller is receiving, i tried contacting the seller and requesting a refund like many other people have but there is no reply, i would like to start the process of getting my money back but the seller was smart enough to set the delivery date about 2 weeks from when i purcahsed it, so i cant start that process until that date, i was wondering if there was anyway around this or if i would have to wait till the delivery date to arrive? Thanks for the help.