Small Claims Court - very confused.

I am new to the site and I am hoping this is the correct section for my post?

I am self employed. A few months ago I was contacted by a nursing home and was asked to quote for garden improvements. I quoted £700 and was offered the job. £380 was spent on tipping fees to get rid of the hedges and garden waste. After completing the work I went to collect payment but I was given the run around.
I submitted several invoices but it was not paid. After waiting patiently I contacted the person who had asked me for a quote and he told me that head office had not paid him, therefore he was unable to pay me. I contacted head office who then told me that they had paid the person who asked me for a quote but he had been sacked because he had not been paying various workmen.

After 5 months I decided to start a claim through the small claims court. After searching on the internet I discovered it was a company who managed 6 care homes throughout the UK. I put their details on the claim I was making.
Yesterday I received a letter from money claim which stated that a defence has been filed.
The following is stated.
I (myself) was not employed directly by the company to provide garden work. I was given the job by a contractor who had been employed by them to find workmen. They had paid the contractor in a timely manner and therefore they was not liable. Liability is with the contractor who is no longer employed by them.
Details of the contractor was provided.

Last night I did some searching online and it is showing that the contractor became bankrupt in 2014. 2 years before he asked me for a quote.
The VAT number provided for the contractor on the money claim defence sheet is not the same VAT number shown online for the contractor.

Moving on I don't know how to proceed or if I can proceed?

Can anybody offer me any advice please?