Barclays Credit Card Complaint

Barclays Credit card department,

Billing disputes New Hampshire

I disputed a charge with barclaycard, in writing, over 2 months ago. I have proof of this as I used an online registered mail service, so I can prove I sent the letter and prove the content of said letter. I closed my account a few days ago, and in my final bill they reposted the disputed transaction. When I contacted them they sent form mail telling me to submit another dispute.