As you pray and wish for more clients/customers, always endeavor to wish and pray for the wisdom to deal with the extremely difficult ones. Some clients are just meant to get on your nerves and it takes sheer patients to deal with them in all ramifications if you seek a good working condition and relationship with your customers.
Firstly, there is the god-complex syndrome with some people who pays for your services, they tend to treat you as an employee, as a hired service provider, your contract with them are not on a monthly payslips. The authoritative client bosses everyone around including the contractors, maybe its just peculiar to this part of the world, but I need to go to other countries first to see how things works with these set of people.
Client-customer relationship isn't supposed to be a dogmatic one, its like going to the market to buy something. You can't boss around sales representatives or market reps because they don't owe you servitude except point of sales services which is being paid for their own bosses or institutions. In addition, been difficult as a client shows are emotionally imbalance a particular person is and that is why they take it out on their staffs and contractors.
Sadly, you can't cut every clients giving you trouble off because most patronising customers tends to have this habits. I can categorize it as an occupational hazard dealing with the likes of these people who could make a businesses day miserable for anyone as an entrepreneur.