Utterly inept accounting department

I terminated all of my services with Cool Ideas in anticipation of moving abroad. Cool Ideas confirmed via email the termination date of my services and the last debits. However, they mistakenly debited my account for my VoIP line after the cancellation date. I contacted Cool Ideas, and the money was refunded to my account.

Since then, the accounts department has persistently pursued me to pay that amount, insisting it remains unpaid. Despite explaining the situation in writing on several tickets over the past four months, no one seems capable or willing to take the time to review the history and rectify this error. Consequently, I am still being harassed by Cool Ideas.

I have reached a point of resignation in attempting to clarify this matter. Could someone at Cool Ideas please take a moment to contact me and rectify this mistake so that I can finally be left in peace?

Please refer to the number provided on the ticket.