Unsolicited Offer turning to be Nuisance

I am member of Virgin Active since 2004, when Germiston club closed in March 2023, we were offered Premier – national membership @ club rate, this was unsolicited offer in writing. Since April, I have been battling with Virgin Active to make good on their offer, afterall, I have never asked for it but because they created expectation, they must deliver! Finish en klaar. The chief reason I want the upgrade being fulfilled is I get denied access in some clubs like Bedfordview, Greenstone and Glenvista. I have called call centre several times, speaking to several agents, all promising that it will be acted upon but all refusing to give u reference number. Every time one call, u must speak to new agent and narrate ur story once more, it is quite frustrating, time consuming and expensive. I have spoken to Ms Nolusindiso, Cindi, Elisha to no avail. I get told IT need to log a call to change “membership type” and there is a backlog hence it is taking time. Even a child would know this is not hardcoded because that’s how gyms makes money. The question is why make an offer and have “seller remorse”?