I actually tried again by following your suggestion to go down the refund route & managed to get to a live chat window.
The operative connected to my laptop via remote assistance, but he only did what I had done a couple of times.
Which was to uninstall and re-install the program but in the same way it failed with me, it didn't work for him!
He mentioned getting someone more proficient to get involved but the connection dropped.
The program does load up on my comp but it just won't accept the activation code, even though he told me it has now been synchronised and should work.
Really don't know what to do now but it's not good having something I've paid for, which is no longer working, after subscribing without any issues for 15 years or so of using it!
Thanks very much for replying and offering your help, I really do appreciate it!