To be fair it isn't just triumph that sucks at customer service. Matter of fact I've never had issues with triumph but I've been under warranty with mine mostly.
I'll share a quick story about a good experience I had with triumph. Back in 2005 I bought one of the first triumph sprint 1050s. Caspian blue. Beautiful bike, awesome power, comfort, sound etc.
I had the bike about 1 week and was taking it easy on her to break her in properly. If I remember correctly I had about 250 miles on her.
My good friend on an 02 BMW k12rs decided it was time to race me and I didn't say no. Lol. After i smoked him up to around 130mph I heard all he'll break loose on my engine. Sounded like someone dropped marbles inside the motor! I barely got the bike home and called my local dealer asap. He said he would be over in about an hour to pick her up. Keep in mind the bike is brand new practically.
I immediately reset the computer as the bike had a feature on it which showed highest speed reached. Mine said 142mph. Lol.
Anyways triumph decided to give me a brand new bike!!! They made me sign all this legal paperwork and I had my new bike within a week! Plus my dealer felt so bad he gave me a Ducati 749s to ride around as a loaner until my situation was resolved!
Crazy stuff!
If you really want bad customer service and a bike with massive reliability issues you should try bmw. You'll pay double for the bike and get even worse service!