I need help.

Dear Sir/madam,
Let me introduce myself, I did postgraduate in Mangement studies. At present i am working as a Marketing Manager for Franchise of one reputed firm. I am proffesionaly perfect but main problem is, i am poor communicating(Business English) to my clients. It became the major hurdle for my profession. I dont know how to improve my skills. Please is there any one who can help/guide me to overcome this problem. I will be thank to you, if you help me.
Thank you

sincerly
salam