Cost Recovery from Lot Owner

The Strata Committee identified a unit which had some leaks which was affecting the common property. The plumber identified the leaks coming from the unit and quoted the costs for repairs. This was provided to the owner which they agreed to pay for. The work order were issued and the work has been done. However the owner has not paid the Owners Corporation for these repairs for several months.

How does the OC recoup these charges from the owner? What should the Strata Committee have done in this type of situation so we know what’s best practice?

Thanks in advance for the responses.