How can a company rise up from a bad customer service reputation?

Thanks 

Simply company should offer what it says and be honest with customers to get good reputation 

The solution have to go in two parallel lines the first one is to improve the customer service , by staff training , equipment’s upgrade capacity increase…etc.

The second line is how to erase the bad Idea that have been implanted it the customer minds the criticality here is that the customer will be hunting the customer services mistakes as per sited idea that have been reached for him by the reputation for this the should be some kind of publicity and advertisement based on the company size and line of business this an goes simply by giving some free services to selected customer and far as advertisement campaign.

Company Should point out  the Positive as well as negative which makes bad customer services . Rectify there mistake happen then there is way to rise up from bad customer services reputation