Funnily enough, even as I was typing out the suggestion you contacted them, Pete, I thought you might encounter communication issues. I certainly have in almost every recent attempted contact with a major concern.
To get a reply with literally just a telephone number on it and no other explanation, or even a few words asking you to call, is a joke.
Best most straightforward trading contact I've had in recent years (in any field) was Dave Craddock, who just says "hello" in the old school way when he answers the landline phone. What a refreshing change that made.