But according to your screenshot in the 1st post you have a bonus symbol on reel 3 too... So...
May have been what DreamRj said a page back, just a visual glitch/bug.
Not trying to defend ladbrokes, but would they really cheat a customer out of a bonus like that if they checked the gameround and found it indeed was supposed to be a bonus.
Might absolutely be a visual bug but they could offer some free spins or a small ND bonus atleast. Doesn't cost them anything most likely and it looks a whole lot better than feeding him bs in an email with their review by "Specialists"