Maybe you got lucky with your ISP, or the apps learned to work around the block. My home ISP definitely blocks Line website. There are plenty of news sites reporting on the blocks, such as [1]
In the very end of the article, there are photos of the Telegraph LLC, the company behind Telegram, just a floor below the currently government owned VKontakte
Re: servers - there are several paragraphs in the middle detailing Telegram's DC move to London. So your server farm claim is still unconfirmed.
Re: the office - from what I gather, they maintain a shell company in Russia that sits in the former Telegram office. The photo merely shows that they may have a large office space, which may have been inherited by this company from their VK split for all we know. I really can't tell from this post if they do any development in their Moscow office.