File a complaint against customer service

I had a lot of questions about using the plugin, but the customer service team just brushed me off; they did a quick, sloppy fix and claimed the issue was resolved—if that’s how they handle things, why even bother contacting them? They ended up making a complete mess of my page. Furthermore, when I raised an issue regarding the creation of headers and footers, they simply told me that the feature wasn't supported—isn't that just undermining their own product? It was a truly terrible experience.