Is the BBB trustworthy?

I have an issue with US Cellular. I went on BBB, and they have an A+ rating, despite many, many complaints. There is a common pattern of a consumer making a complaint to the BBB about US Cellular, and then US Cellular replies with a generic "we're sorry, customer service is our top priority blah blah blah" response, and the BBB accepts that is the company taking a reasonable faith effort to resolve the issue.

If you look at the US Cellular facebook page https://www.facebook.com/USCellular , it is LOADED with unhappy customers. I know many people locally that are extremely upset with their service. People are getting double or triple billed in one month, not billed at all, phones randomly getting shut off despite being paid on time, 3+ hour wait times on the phone for customer service, website login not working, or only working intermittently, etc.

Something is fishy there..