Including the number again my whatsapp list

Hello,
I ,susmita halder, now a days was facing a serious problem in using whatsapp.messanger. sir, some one has blocked my number from his/her phone .so I want to include his/her number again in my whatsapp contact list.
please, sir, please, give me a favor and help me to overcome my problem.
I, hope that you will definitely help me. I,am anxiously waiting for your answer.
--thanking you
susmita halder