Unable to delete Role - AWSServiceRoleForAmazonOpenSearchService

I have created AWSServiceRoleForAmazonOpenSearchService role for opensearch domain name 'water-temp-domain', after completing exercise I have deleted domain and all services from AWS to avoid any charges, I am surprised today £59 charge on my bill, I am trying to delete but can't do that when i check status of the deletion i am getting following error even domain is not exists. : Please help me { "Status": "FAILED", "Reason": { "Reason": "At least one domain is using service linked role arn:aws:iam::645351934927:role/aws-service-role/opensearchservice.amazonaws.com/AWSServiceRoleForAmazonOpenSearchService.", "RoleUsageList": [ { "Region": "eu-north-1", "Resources": [ "arn:aws:es:eu-north-1:645351934927:domain/water-temp-domain" ] } ] } }