Barclays Credit Card
Card missused

Hi

My barclay credit card is used by someone online without my concern, I informed the same to barclay credit card at the earliest when they had not released the payment for the same also mailed them dispute form filled and signed my me. They again asked me to sent the same at the PO Box address courier person did not accepted the letter because of PO address so I mailed it through post and m not having any acknowledgement for the same and barclay people say that they have not received any letter from me its already 24 days past since I mailed the letter to them. Know they are asking for the payment of the same,

Please do tell me what should I do???

Thanks

Dipesh M sheth