You can't make them pay for the repairs up front, but you can sue them for the cost to make the repairs: when someone negligently, or carelessly, damages another's property, they become liable, for financially responsible, for the cost to repair the damage. If they have acknowledged the damage in writing, you should have an excellent chance of winning. So arrange for the repairs, keep the proposals/estimates, invoices and proof of payment (e.g. cancelled checks) for the work, and sue them for the cost you had to pay to repair your premises.(However, if you have applicable insurnace, the easiest/quickest way to get compensation would be to submit an insurance claim.)