At some point customer service died. Businesses of seem to no longer be interested in dealing with customers. Good customers come in all shapes and sizes, and often don't exactly fit a cookie cutter. It's frustrating to see businesses just cut and run the moment something becomes a problem that needs more than a series of pre-scripted responses to be resolved.
Wise customer service is amazingly good though. I'd much prefer to use a company that spends 100% of the time on 80% of customers than one that spends 80% of it's time on 20% of the customers OP can't even provide proof from the tax office of being at that address, it's an angry rant rather than the whole picture. Would you go into business with him with nothing but a phone bill as proof?
Well, the article says otherwise. I think "The document was rejected because it was a tax invoice, not a bill." is a pretty lame rejection reason.
That being said, I didn't quite get the solution Wise suggested. Don't they already have a lease document for the new office? It looks like the author has omitted some crucial detail.