Discovery Vitality - booster or bummer?

I am at the Virgin Active gym and at the end of October I activated the Gym Booster through Discovery Vitality. November my full debit went off my Discovery account, a week later I phoned and queried the cashback - 75% and if criteria met also the additional 25%. "Don't worry it will come through" I was told. 2 weeks later still nothing and a call was logged. At the beginning of December the next debit went off. A week later I called again and was told they would escalate the matter. A week later with no call back I called again and was told again "We are escalating it" ... a number of calls and promises brought us to January and the 3rd debit went off with no resolution. Last week I was told they have found the issue and would sort it out and ensure I receive my cashback ... suffice it to say that today, 10 January 2020 I have still not been able to get their stuff together and resolve the issue.