Auto and General takes useless to new levels

I have never dealt with a company more useless than this. When you phone their number they transfer you and then the line goes dead. When you phone again you wait for ages and there's no music and no indication of where in the line you are. When you try and submit a claim or a callback through their website you can't register (even after trying several browsers). You can't get immediate access via a one time password. The callback also does nothing. How am I supposed to contact them about a claim write a letter?