Sometimes browsers or systems do hang, but unluckilly this is also the most common reason or "excuse" that customers give as well. Hence my suggestions to help you to next stage.

If you receive no reply then you need to go back to your credit card company with Opdo's lack of response and reiterate your claim that no transaction was fully completed or confirmed and that Opodo are unwilling to provide proof to support their position and to prove that your claim is incorrect.

If Opodo do not respond, you therefore hold the credit card company responsible for resolving it. Your Uncle will have problems with explaining why when he wasn't certain whether a booking was made or not - evidenced by the fact that he e-mailed Opodo - when he received no response he decided to assume based simply on the fact that the credit card transaction hadn't been processed - that no transaction had been completed. It would have been prudent to call and make sure which he apparantly didn't do.

I fear that you will find that it was completed and an automated e-mail sent but at least my suggestion gives you a fighting chance.

Good luck.