Not withstanding all of the above, I think I would go a little tougher (or at least appear to do so).
Firstly (after approval from the comittee) I would issue an invoice for the previous year’s levies with the proviso that anyone who could prove a payment had been made (with the threshhold for proof fairly low) to have the proven amount credited against their account.
I would also add that anyone who hadn’t paid the full amount (or anything) would have the penalty interest of 10 per cent waived provided they paid up withing 30 days.
I would invite anyone who had paid but who did not have any evidence of payment to submit a notarised statutory declaration that they had paid, explaining how, when and why they had no proof, again within 30 days.
And finally I would offer the option of negotiating a payment plan for anyone who couldn’t pay what they owed, on a case by case basis, subject to negotiation.
Hopefully that would flush out the cheats without causing undue hardship to an unlucky few or, indeed, to those who had paid in full and were effectively carrying non-payers.