How very annoying! I'd write again, and ask them to send you by email a full transcript if they can't enhance the image so that it can be read. - A full transcript would be better from your point of view than a refund.

In your message you said "...the address, place of birth, cause of death, age (although given on the index)...". Did they actually give all these details in the index entry, or just the age, and was this correct to be your Jane?

Sue