At the beginning of my application process, I sent the invitation to one of the school teachers to be the school counselor, and he received the invitation and started. Later, he told me that another certain teacher is assigned to be the school counselor, so I deleted his information and filled in the info of the new counselor. However, the counselor told me that he didn’t receive the invitation, though I rechecked that I typed his contact info correctly. What should I do ?