Cabot/Morimer Clarke - claim now statute barred

Hello there I hope you can give me some advice. A claim was made against me on 6/08/2014 by Mortimer Clarke/Cabot in relation to a Vanquis account. It was my belief that this debt was statute barred and informed them of so and filed my defence to this affect. The claim was stayed and was told no further action would be taken as they were waiting for documentation from their client to prove otherwise. I have received a letter from Mortimer Clarke today stating that the last payment made towards this debt was on 31/10/14 and therefore as the claim was issued against me on the 6/08/14 the debt is not statute barred and are entitled to enforce the debt. As the debt is now statute barred are they able to enforce it given the original claim was issued on 6/08/14? Please can you advise on what I should do!! Many thanks

Cabot/Morimer Clarke - claim now statute barred