How to get my CC APR lowered when they refuse.?

I have a walmart Credit card and they refuse to lower the 22.90% interest rate,they told me on the phone that i agreed to it because i didn't close my account when they sent me a message telling me my apr would go up,it started at like 19% which i shoudlve never taken to begin with.But ive called them,told them i would switch to another company,my other card has allot better rate,ETC,they basically say well go ahead we Will NOT lower your APR period,no matter what you do.So i closed the account,they said they would lower it IF i defaulted,they could then do something for me lol.any advice,im paying it off,but a lower APR would help me do so faster,transferring the bal is not really an option.