kathieathome, I would put in your appeal as many reasons for the adjudicator to rule in your favour as possible.
Eg 1) You were only in a bus lane so as to turn left.
2) The suspension date was wrong
3) Etc, etc, etc.
Again I would look very, very carefully at everything that the council has sent you. In my case part of my appeal was that the law states that the council must put the amount on any increased fine on a
PCN and Haringey didn't. Read the law, (most of it is in the LLA Act) and then check that the council have complied with every part of it. If they haven't then put it down in your appeal.
If the appeal is unsuccessful then state that you should only pay the reduced amount as you should not be penalised for appealing. You may find that the adjudicator will agree with you and move that the council accept the lower rate. If he/she asks you why you didn't pay the £50 before the appeal tell him that you thought that this might be construed as an admission of guilt.