Season ticket and provision of goods and services act

Hi,
I have a season ticket on the Thameslink line costing over £4k a year. With the recent reduction in service (sometimes 1 train per hour instead of 4) and overcrowded delayed running services, I wondered how this sits with the provision of goods and services act? When I took out a season ticket it was on the basis of an expected level of service that is not being met. I've been claiming delay repay but have reached 50 claims in 3 months so they are now declining claims despite the circumstances. I wondered if I could go through small claims for the period 21 May to mid July for a refund against my season ticket?? Any one else thought of this??