If you are a revisiter, you don't need to be polite because of your close relationship. Simply say, "I'm sorry I haven't come to see you for a long time." Or "We meet again. Two months ago was the last time I was here? "
Most return visits are due to the need of etiquette, and greetings should be in a thank-you tone. Usually, you can say, "Thank you for coming last time, and I'm here to thank you today." "The last time you just left, I thought, thank you again anyway!"
If you refuse a customer many times, you can hand in a note that says, "Would you please give me ten minutes? I want to ask your advice on a business problem. " The note aroused the curiosity of the purchasing manager-what questions did he want to ask me? It also satisfied his vanity-he asked me for advice. In this way, obviously, the salesman was invited into the office.