It's understandable to get frustrated at Coinbase, but in many cases I've found it is not their fault. They are known as a "high risk" company, because fraudsters have taken stolen credit cards in the past and purchased Bitcoins, then transferred them away from Coinbase and the money is gone forever - no such thing as a chargeback there. The credit card companies have wised up to it and now will now block these transactions by default. Different institutions have different rules around it, some card providers will send you a text asking for verification and others might not notify you at all - you'll have to ring your banking provider them to tell them it is a valid transaction, at which point they will allow it to go through in future.