Insurance

Hi Would like to hear what people think to this Last year my brother noted a crack on my outside wall only 3ft high not going through the damp proof course he told me to keep an eye on it. In Febuary this year noticed crack now over 10ft high it was following the course of the mortar but has gone through two half bricks at the top. Notified insurance company early March. In May had a Loss Adjuster come out he inturn sent a structual engineer in July. Had latter back from Loss Adjusters stating that the crack Might have happened due to a earthquake tremor that happened in 2001/2002. My insurance company have said that due to the fact I wasn't insured with them at the time of the earthquake they have asked me to speak to the insurers at the time. What I would like to know!! If the crack only appeared last year isn't my currant insurance responsible?? The Loss Adjusters who sent out a structual engineer ruled out subsidence which I am glad about. I have got intouch with pervious insurance company but I can see I am going to be piggy in the middle and the crack is going to get worse with the bad weather coming. Any advise would be thankfully received