Часть Non-Competition Clause

ii) canvas or solicit or entice or endeavor to canvas or solicit or entice away from the Business in whole or in part, the custom or business of any Client with whom you have had personal dealings; or

iii) approach any client of the Business with a view to or with a purpose of enticing the business, in whole or in part, or custom of such client away from the Business

Заранее спасибо

I have given this barber my custom for many years. (Я давний клиент этого парикмахера)

In this case, use Заказчик for Client. Or you can switch the terms around.