A customer pays a monthly bill for a specific service. The company wasn't able to provide this service for three days. The customer calls me since I work as a customer service representative and he asks for a refund or an additional three days as a a substitution. The policy doesn't allow me to give any kind of substitution in this scenario. I can't even place a complaint for him because it will be useless.
Here's what I would like to say and please convert it into a polite speech:
No substitutions by any means or under any circumstances.
I wish If I can help you but it's something out of my hands.
If there's something I can do, I would have done it but it's impossible to substitute.
Edit: I wrote this story so that you can understand the context only. I'm not asking "What to do in this case?" I'm asking about how to say the four sentences mentioned above in a polite way? Please, answer me (at least, for the sake of learning English). BTW, sometimes customers sign the contract and agree that the will not receive any substitution for occasional technical issues but they still ask for it.