Flight Cancellation

I was a loyal member of Discovery Vitality - always meeting my goals, being part of Team Vitality and Gold Status for many years. In 2017 I used the Gold 30% discount to book my flights to the UK to study abroad. I subsequently had to cancel my return flight because Discovery wanted to charge me 2 times more than what I paid for the original flight. They promised I would get a portion of my money back in 6 to 8 weeks. Its now been 12 weeks and upon speaking to them - they seem to have forgotten to do a refund. This is so frustrating and extremely disapointing - I have always given Discovery the best reviews and advised all my student friends to go onto Discovery when they start working - this makes me feel otherwise.