I ask about the CPS they are with because sometimes they hold a copy of certificates and it may be worth getting in touch with them to see if they hold a copy. I find it hard to beleive a company big enough to have a server does not have cloud back up! I am a sole trader and I have cloud back up, as well as copies sent through email and for larger installations I write separately to CD a copy. Anyhow it is what it is. It does say on the certificate the it is an important document and to keep it safe, not much use I know I feel for your predicament.