This is, unfortunately, in line with my experience with the "RYET Official Store"
https://chinertown.com/index.php/topic,4834.msg82962.html#msg82962Very slow response and they never came back addressing the technical problem.
Finally, they asked me to return the product to them, shipping it directly to China at my cost.
They claimed, they would cover the cost and reimburse everything - by that time I had lost trust completely and used the AliExpress return.
They complained heavily after that and I am since then very careful with RYET products.
Options I see for you:
Even if your buyer protection expired, you could still try to involve AliExpress to moderate.
If this does not help, I see two options for you:
Use spacers. Even if Q-factor will be off, you should be able to center the crank and get it installed with adding more spacers (careful: spacer outer diameter needs to be large enough, so the spacer does not go "below" the preload ring.
Other option I see: after the unpleasant experience with RYET, I purchased a Rockbros crank (175mm is not available from all carbon crank suppliers).
The Rockbros crank has an ugly marking, that meanwhile I covered with a piece of PVC self adhesive foil.
Rockbros is very helpful, I even managed to get spare parts from them - so maybe they are willing to sell the titanium axle as spare part?
To me, the RYET crank and the Rockbros crank look very similar and since they are both available in 175mm, I assume they come from the same manufacturer.
The Rockbros crank, however, has a titanium colored axle vs. the black color of the Ryet axle.
I assume the difference is in the axle and this is also were the issue with RYET is, so maybe the Rockbros axle would solve the issue and mount to the RYET crank.
Note this is only my assumption, none of the above options is perfect and all come with trouble...
