You were right about immediate implant placemetn and immediate restoration. Your dentist did not want to do so probably because either he does not do that at all (it is pretty technique sensitive) or he could not charge you enough (20% more normally). Because the soft tissue always follows the bone. There must have been no enough bone height or/and thickness before the extraction. Following the resorbed bone the gum line went up and thus the tooth had to be long, in your case, very long. The gingival recession always happens. With the immediate placement technique, the recession can be limited to 0.8mm or less. With delayed placement after the extraction, it on average can reach 2mm or more, which unfortunately has happened to you. As for you, probably I can say it has failed, aesthetically. Go find an experienced one who knows how to do bone graft to augment soft and hard tissue volume and bring down the gum line close to that of adjacent teeth and redo the implant restoration. It is hard for both you and your dentist tho. Good luck.