Is it a coincidence that the value of bitcoins had also gone up considerably from the time I submitted my purchase?
No. This is how
Ycombinator projects work.
Coinlab/Coinbase/Coincrap - Multiple cases of stealing from users through the "canceling BTC sale when price goes up" scam, amplified by "pay anyone complaining on the forum" double-down. In any event their burn rate takes them out of the picture this year, so damage should be limited, but try and sit at a safe distance.
Going by the density of forum complaints I'd venture a guess that even the double-down has by now proved to be too consuming.