Ah, I think I see where the misunderstanding comes from. I wrote:
"the interest rate 15.469008%, or $14.08 per month."
I've now edited that to clarify that the interest rate is the yearly rate:
"the interest rate was 15.469008% per annum, or $14.08 per month.
UK credit cards currently charge an exorbitant 35%, and US credit cards are closer to 20% I think.
!BBH