Item not as described it was gold plated

[robuk-cb6ediz6]

I purchased a 9 carat gold ring apparently vintage Hallmark. Been wearing it for a couple of months and I noticed it started to fade so I took it to a jeweller and they confirmed that it was a gold plated on top of 925 Sterling silver. It’s past the return window so what can I do? I paid £80 for this 

[**peaseblossom**]

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