Removing cat odor from concrete flooring

[George Wade]

All, Against the rules of the lease, a tenant brought a cat into a home (New Brunswick, NJ area) and placed the litter box in an unfinished basement (concrete floor with masonry block walls).  The cat has been removed by the tenant, but I am now trying to find a company that will remove the odor.  Have received a quote from ServPro, but they will not provide any guarantee with their work.  Hoping the fine people on BP can recommend other companies that offer the service.  Thanks in advance.  George