Unhelpful & Unsympathetic attitude of Bookeeper, NOT Practitioner

A pensioner discount was requested and then given on an account The invoice was received and within 2 hours of receipt of the invoice I effected an EFT. In my haste to make the EFT (as I consider that as a service had been been performed, it is right that it be paid immediately), I paid the full amount and did not notice that there was a sentence in the e-mail that said "Unfortunately no refunds or credits will be given for Discounts not taken". When I emailed the proof of payment, I thanked them for the discount, but said I had paid the full amount without deducting the discount and please would they refund me the discount? I was told this was not possible due to VAT and 'other reasons'. I then suggested that the VAT be deducted from the discount as a means to resolving the problem but this was also rejected. I feel that some leeway could have been extended, because as a pensioner every Rand has to count But there was no sympathy for my explanation, and no refund.