Hey! So there is a special software that helps the owners of the company to optimize the work with clients. I can recommend you two programs that work with a bang. These are zendesk and salesforce. But which is better to decide for yourself. You can read an interesting article about the capabilities of these programs, here it is:
zendesk vs salesforce. I have been working with zendesk for about 3-4 years on various projects. All the questions and problems that arise - the guys solve quickly and efficiently.