Unacceptable

I have been a great supporter for many years but its official- the support is shocking! I returned a product and they (accidentally on their part apparently) gave me only some of the money back for this. I contacted them and they sent me a voucher that was valid for 24 hours which I didn’t receive until after it had expired. When contacting them to say i need either a new voucher code or my money refunded as i requested, they said they wont help me. They will not give me my money back. Unacceptable!