I have a similar story to you, I have been a member for quite a while but only started to play against others a couple of weeks ago, mainly the single hole Chelsea match up.
Obviously there is a bit of gamesmanship with players waiting until the last moment to take a shot and that doesn't bother me at all.
I had one player who got a bit impatient when I had a loading problem which happens occasionally but other than that the vast majority have been polite when chatting but one player called [naming players not allowed] wasn't just rude he was vile and obscene. I wont write what was said because it really was disgusting.
His first comment was to ask if I was gay and after I responded with a curt reply there was a string of swear words which were filtered out and a further comment which was worse than anything else said up to that point. He had only been a member for 1 day!
He has been reported and I have had a reply that an investigation was underway. I think that the suggestion to ban players after 3 complaints, which I also passed onto the complaints department, is a good idea. I suggested that using ip addresses is one way to prevent further accounts being set up by a banned player.
I think this type of abuse can be reduced if we the players report it straight away and lobby the WGT team to take these things seriously.