Shocking customer service

I am a Discovery client since almost 10 years and it is such disgrace to have to deal with them. They claimed one of my doctor visits from my savings account instead of my included benefits. 3 phone calls and 5 emails later the error is still not fixed. They are very quick to take your money but if they make an error and owe you they take forever to solve it and just don't care. Zero customer service. Every single time I phone they say it will take 2-3 working days and that is now going on since 2 weeks. It is horrible to deal with them they have no sense of customer service the call center agents have no clue either. What am I paying for here??