Been Waiting a Week for Support on Limit Increase

Contacted via the chat one week ago trying to increase my top-up limit. Was told it was being escalated to the appropriate team and I would hear back in four days. It’s been seven now and still nothing. No-one responds on the chat, can’t even get through to a live agent. I’m a Premium Customer, which I’m led to believe comes with Priority Customer Service, however I’m yet to see evidence of this.
If this limit can’t/won’t be increased then I’ll be asking for my Premium fee back as their service will be totally redundant for me.