I agree with ajberry. I too would be inclined to think that there is more to your credit file than meets the eye. A small amount over a credit limit if rectified within the same month won't make a massive impact on your credit file.

Rate is for risk, therefore if you are a high risk then the rate would be higher. If you don't feel you are a high risk, then personally, I would obtain a copy of my credit file and see what is on there. Welcome cater for the "sub prime" market. UCC also deal with applications for Black Horse, which only compounds that if Black Horse won't agree to the deal, then there must be something that is detrimentally affecting you.

If you really don't like the APR, then don't sign!