Where are the certificates?

Having purchased my house 4 years prior and recently sold my house I had to get all the certificates of compliance. The inspections were carried out only to identify work that was never done when I took ownership. I never received the original certificates from the lawyers and slowly managed to work out that DOSS had performed the work. The issues related to electrical, plumbing and even the electric fence. It is very easy for deniability so just contacted them over the plumbing issues. Eventually got them to come round , after a short meeting they tried to raise doubt over the age of the geyser and the the fact that the company had changed hands. They weren't able to provide the certificate for the previous work performed. Another individual confirmed from insurance records that the geyser was a 2010 model which required all the necessary work, drip tray and overflow issues be resolved.

I have written back to the company to request comment but they now choose to ignore my emails.

I have requested they pay for the work that was never carried out when I purchased the house resulting in my incurring the costs - this is not acceptable and will now approach NABISA, Law Society and small claims court to ensure the payment is made.