If all five PCNs were received together in the mail, then you have a good case for requesting cancellation of four of them and offer to pay the first one. This is because you only became aware of committing these offences in the local streets near your old friends house, when the PCNs arrived. Essentially it is an argument that the penalty is disproportionate.
So I suggest you submit representations for all the PCNs together, apologising for the driving error based on being totally new to the area, living some distance away at <where you live>, and state plainly that you consider paying for all 5 PCNs is a disproportionate penalty, and that you admit error and are willing to pay for the first PCN.
