I served a 14 day notice to my tenants to remedy some rather nasty stains on the carpet in the lounge and in the bedroom, they have been in only 4 and a half months. When I went back the stains were still there, they said they had tried to move them but were unsuccessful. They themeselves said that the carpet is effectively ruined and have offered to pay to replace the carpet by instalments. The carpet was not new but was in good condition. What would you do next?