Internet banking not working again

When i try to make a payment i get told that somebody detected a 'sim swop' on my device that's why everything has been disabled. First of all there has been no such sim swop so I don't know where you got that from. Secondly, if this did happen what does that have to do with my logging on with my PC? I don't get the connection so I need an explanation. I am so unhappy with this service its unbelievable.