If you arrived more than 5 hours later than scheduled you should consider a claim under the EU regulations. A delay of more than 5 hours means you would be entitled to claim a refund of your flight ticket.
The precise details of your complaint are unusual and you should in the first instance write to the company, making your claim under Regulation (EC) No 261/2004. This law specifically establishes rights in relation to long delays. If your delay was greater than 2 hrs and less than 5 hours, you were entitled to refreshments. If they failed to provide these, you should submit a claim for reasonable refreshments with attached receipt.
If you get no joy, you can complain to the appropriate national body. In the UK (which would apply to this flight as you can choose either the point of departure or arrival) the competent body is the
Air Transport Users Council (AUC),
www.auc.org.uk.