The multiple select checkboxes of Custom UITableviewcell is not selecting

I use below code for sending my uitableview cell to editing mode:

- (UITableViewCellEditingStyle) tableView:(UITableView *)tableView editingStyleForRowAtIndexPath:(NSIndexPath *)indexPath
{
    return 3;
}

when I enable editing mode the checkboxes of editing mode appears in my cells but when I click on the cells only the background changes, the checkbox not selecting or deselecting.

Please see below image:

Does anyone have any idea about what is wrong??

I set the selectionStyle of the cells like below:

    [cell setSelectionStyle:UITableViewCellSelectionStyleGray];

now, checkboxes is checking but when the cell is more higher, a line is adding to center of cell too!!