Ask someone to recommend an accountant. It is possible that you're due a refund!
Be upfront with the accountant that the outcome is likely not to result in a fee to him but you'd like to discuss your tax affairs. Accountants are usually happy to chat with someone over coffee even if there's no fee likely to result. We did this recently, the visitor eventually recovered 2,500 in tax - no fee to us but it left a lot of goodwill behind - it's a long road.