Here is what I will do based on my lease agreement and law.
1) repairs should not be reason for tenant to stop rent payment.
2) my lease requires written notice for all repairs. (Mold is from water damage, which must be due to unreported water damage.)
3) all payments will be applied to repaire/late fee/fines before the rent
4) if the payment does not cover the rent after all repairs/late fee/fines, I will sent the tenant a rent-demand notice. And if no corrective active, I will sent tenant eviction notice.
check your lease for correct action.
Good luck!