//now it has reached the 10,000 signature threshold ,it has to trigger a Govt response. //
Which could be 'don't call us we'll call you', or something similar. Only after 100,000 signatures are issues 'considered' for debate in parliament so that isn't set in stone either.
https://www.gov.uk/petition-government
It seems to me that the pensioners who are worst off are those who have small private pensions that take their income just over the level at which they can claim extra benefits. Those who are able to claim are not badly off at all.