Hello!

We are sorry for your unfortunate experience from 2 years ago. The delay in processing your transaction was related to a huge workload of our services which cannot be managed due to the insufficient technical capacities at that time. It's vital to mention that we've significantly developed our services since then: the average time of processing has been lowered, the number of failed transactions has also decreased. In addition, we hired more support staff and added a live-chat thus considerably improved customer experience.
Speaking of your case, your funds couldn't be converted to DOGE due to technical issues on our side. Once they were fixed, we returned funds that you sent us, namely 3.21793846 BTC excluding BTC network fee that should have been withdrawn in order to deliver assets to your wallet.
Please understand that we had no intention to withhold your funds as it is not profitable for our team to hold a rate at a disadvantage for our customers. How it works: you got a higher rate and higher sum, hence we had a higher fee from that transfer subsequently. Be aware that rates are literally beyond our control and only markets have been establishing the rates and our end of the bargain is to broadcast it for our clients. That's the principle of how any exchange works and the only option for us to have a partnership. Also, if you check our ToS - https://changelly.com/terms-of-use, it is clearly stated that Changelly is not liable for any losses of profits as the crypto ecosystem is quite unstable and volatile.
All in all, as we can see from our database, your transaction got failed and couldn't be converted to the resulting currency, hence we've refunded your coins. In order to smooth things out, we may discuss the reimbursement. Please DM us. Thanks!