Expetionally pathetic customer service by Air Asia

Air Asia changed my flight times, gave me the option for a refund which I opted for - it's been four months now and the refund has not been completed (they claim it should be processed within 30 days). Only option to contact them is via their useless ChatBot called Bo who only re-assures every time that my case is very important to them and that they are urgently looking into it, but nothing ever happens. Just need them to give me my money back as promised.