HORRORIBLE Customer service. Non existent

I have been struggling for 3 months to get a credit increase on my card. Every time I call in they say they will escalate it to management. No one calls back. That's all I hear when I phone in. It's like that's what they are trained to say. VERY BAD SERVICE. Have to hang on 30 minutes at at time. Who pays for these calls. Rather employ people who are competent to do the work and think for themselves