Without proof there is nothing that can be done sorry and as deadmonstor said he will happily deal with it to make your experience on zarp good also use the ban request tamplate here-

Name - (What is the accused person's name?)
Steam-ID - (What is the accused person's Steam-ID?)
Evidence of Steam-ID - (Screenshot or video of the accused players Steam-ID)
Server - (What server was this on?)
Time and date (CET) - (When did it happend?)
Other comments - (Anything else you want to add?)
Reason - (What rules did the person break?)
Story - (What happened?)
Proof - (Any proof (video or screenshot) that clearly shows what happened.)

Without proof there is nothing that can be done sorry and as deadmonstor said he will happily deal with it to make your experience on zarp good also use the ban request tamplate here- Name - (What is the accused person's name?) Steam-ID - (What is the accused person's Steam-ID?) Evidence of Steam-ID - (Screenshot or video of the accused players Steam-ID) Server - (What server was this on?) Time and date (CET) - (When did it happend?) Other comments - (Anything else you want to add?) Reason - (What rules did the person break?) Story - (What happened?) Proof - (Any proof (video or screenshot) that clearly shows what happened.)