Dealing with complaints

What seems to be the problem?

What happened exactly?

I`m sorry to hear you were not satisfied with the service.

I`m afraid it`s not our policy to ...

I understand you`re upset, sir.

I must apologise for the treatment you received.

I`m just trying to understand the problem.

How were you using the ...?

Did you read the instructions that came with the ...?

I promise you I`ll ...

I apologise for the inconvenience this has caused you.

We`re sorry that you`ve had a problem with this product.

We`ll do our best to get your ... (product) working as soon as possible.