Discovery always rejected valid claims due to staff not reading properly

I just got a claim rejected due to an invalid practice number. I went to verify the practice number myself on PCNS - it immediately showed as valid with the correct name etc. of the service provider on my very first query when I inserted the practice number. This is so unacceptable. Eight out of 10 times when I submit a claim myself discovery rejects in for invalid reasons - mostly because they do not read. Or maybe for other reasons? I am very busy and to have to always have to resolve issues that are not necessary in the first place is extremely frustrating. All I ask is for Discovery to apply its mind or at least train their staff.