I just checked the moderation logs and @Ahmad94 has deleted it. Staff don't know if the other staff has taken action on reports or not. They just read the report and carryout the moderation. So it is better to contact a staff personally and ask him to delete the poll. Reports can be read by all the staff and by seeing the poll still up on the top of the thread, they will surely delete it after reading your request.
You create a new one and I'll make sure this doesn't happen again.,