I tried to buy on Coinbase two seperate times during big dips in both Bitcoin and Ethereum and both times they said the purchase went through, that my coins would be in my wallet immediately, I clicked the confirmation and everything. But nothing happened. Nothing in my wallet, no pending transactions from my bank account, nothing.
I took out a support ticket both times and only got a response on one which said that they were considering adding new cryptocurrencies to their exchange at a future date, which had absolutely nothing to do with what I wrote them about. I responded asking them if they even read my initial complaint, but of course they never responded. I've since taken all of my Bitcoin, Ethereum, and my future business elsewhere.