Exorbitant interest rates despite good credit record

I bought a new vehicle in 2016 and signed the contract agreement with Wesbank at an interest rate that seemed excessively high (15.7%). The F & I person at the dealership assured me that this was as good as I was going to get. I was in a hurry to conclude the deal, so I didn't phone or ask around. I signed the papers and went on my merry way.

We're currently buying a new car for my wife, and having seen the low interest rates she was being offered by all the banks (despite the fact that we have the exact same credit profile), I phoned Wesbank to hear if they'd be open to re-negotiating my interest rate which is excessive, given my good credit profile. What I got from them was a very curt "you signed the contract, so no".

Great job Wesbank. Not only are we not going to finance my wife's vehicle with you (despite the fact that you offered the lowest rate by .5%), I'm going to refinance my vehicle with another bank as well. Now you lost two cars for a couple of hundred bucks in interest payments.

I'll can't believe I actually considered moving to FNB. "How can we help you". Sure...pft