Small Claims Court - name of defendant change

[JanFeat]

Hi, I have issued county court proceedings in the small claims court against a boarding kennels that ended up killing my dog. The information I have on them is husband and wife trading as.... and this is the information I put on the claim I made. I have just spoken to the curt and they said that the defendant has to be one name only and it will cost me £100 to change the name. Or I could put it on two lines and have both husband and wife. Due to Covid nobody is answering phones and I cannot find out who the actual proprietor is, the court told me it has to be one person only. So, I am hesitant to put the man in case it is the wife's business - how do I do names on 'separate lines' as the court said was an option and will it cost me double to do so? Really confused... Ideally I would like to find out the sole proprietors name