Barclays Credit Card Complaint

Barclays Credit card department,

Credit line increase/decrease California

My credit limit with my card is $8000.00. I wanted to make a purchase for about $15000.00 on the card, and so therefore, I prepaid my credit card by $7000.00 to effectively increase my spending limit to $15000.00. The card issuer did not restrict me from making the prepayment and therefore I did so. When I made the purchase, it was declined. Upon talking to customer service at the credit card company, they said that the act of prepaying the card does not increase temporary increase the credit limit - contrary to intuition of providing the card company with a secured prepayment. I then authorized a hard pull on my credit to see if the limit could be permanently raised to $16000.00, taking into consideration the prepayment. The hard pull was performed and the request was denied. This hard pull will impact my credit for the next two years, and the company would not allow me to consolidate this hard pull with a previous hard pull I made to increase my credit line in - 2015. In summary, I would like to make a $15000.00 purchase with my card, and I prepaid the card by $7000.00 thinking the limit of $8000.00 would be effectively raised to $15000.00. This card company will not allow me to do so, and I believe it should since I provided a secured prepayment.