None
The contracturalcontractual chain is you <-><-> warranty company <-><-> (potentially others you don’t know about) <-><-> service provider.
Should something go wrong, you would sue your warranty company who might (itsit is up to them) then sue the service provider. Notwithstanding, it’s likely the service company owes you a duty of care and would be directly liable to you for a negligence claim.