Your seedlings look suspiciously like Hylocereus undatus aka dragon fruit. This is a vining, climbing cactus which can grow to a very large size - usually trained up a trellis, or ropes in a greenhouse setting. When large enough, they produce enormous, fragrant, white nocturnal flowers that last just one night. I can’t be certain that that is what they are, but do look like it.
Definitely NOT Echinopsis, which as you guessed should be globular, and would be much smaller and slower growing. Did you buy the seeds from a reputable supplier? I ask, as there are a lot of scammers around (especially from China) who sell ‘rare’ cactus seeds which frequently turn out to be cress, squash or even grass.
If your supplier was bona fide, I would make a complaint, for selling ‘not as described’ seeds, but with the time elapsed since purchase, probably not very hopeful!
The Abbey Brook hybrids are quite beautiful, and were bred by Brian Fearn, and deservedly popular. I grow a number of Echinopsis hybrids, but mine are mainly American Schick hybrids and others from a UK breeder.
Hope this helps.