Yes I have dealt with them trying to sort out an F1 'To Finish Top 6' market at the 2019 Japanese GP where they initially settled correctly (at the time of the podium - about 15 minutes after the race finished), then 3 hours later they re-settled the market incorrectly after a stewards inquiry had given one of the top 6 drivers drivers a post-race and post podium time penalty.
As you will know, in F1 the official results at the time of the podium taking place are what Betfair use to settle the numerous race markets.
Trying to get someone to understand that they were incorrect to re-settle the Top 6 market as a result of a post-race and post podium stewards time penalty decision was impossible and I was not able to directly communicate with someone in authority. This was shortly after they finished their customer service telephone line.
Your experience of Betfair via Twitter might be a good one, mine certainly is not...so your 'That's bollocks' is utter bollocks LeTiss!
Have you actually used them or are you just guessing?