Sounds familiar ! We claimed almost 2 years ago for serious damage following the very wet winter 09/10. They refused. We complained and the matter is still being considered by the UK Ombudsman.
Like you, they refused to renew the policy......which leaves us without basic third party and unable to get any because of the damage to the property.
The Consorcio.....Same problem ! The consorcio website stipulates that the tax paid shall be .08% of the "Sum Insured". Our "sum insured" was £1 mill. However, Intasure only payed for a rebuild cost (a figure applied by them, not me). The result is that we are grossly underinsured with the consorcio. The point of the Consorcio is to protect the insured for abnormal events not covered by the insurer and to protect the policyholder should the insurer be unable to meet their liabilities. It is required by law in Spain, and not just for properties; your car insurance also has to comply. My solicitor mentioned "breach of contract" and I can understand why "revenue evasion" was mentioned to you. It is, after all, a tax.
For those who think they are saving a fiver.....I suggest you read your policy VERY carefully.
One example:......... If you happen to live in the Sierra Nevada or anywhere at risk of avalanche. Buildings cover section 5...."We will pay for damage caused by avalanche"........... but not for damage caused by landslip or weight of snow !! As clear as mud and open to be interpreted any way they choose.
If you receive any response from the FSO, I would be very interested